Method for transmitting and receiving signal in wireless communication system, and device supporting same

ABSTRACT

The present disclosure relates to a method carried out by a terminal in a wireless communication system, and a device supporting same, and more specifically relates to a method comprising a step of obtaining a message A comprising a physical uplink shared channel (PUSCH) and a physical random access channel (PRACH) preamble, and a step of transmitting the message A, wherein the PUSCH is transmitted on the basis of information related to a PUSCH configuration for the message A that is being received, and, on the basis of the information relating to the PUSCH configuration comprising information relating to the instruction of a code division multiplexing (CDM) group for a demodulation reference signal (DM-RS) for the PUSCH, the CDM group is set to be a group indicated by information relating to the indication of the CDM group among two pre-set groups. The present disclosure also relates to a device supporting same.

This application is a continuation application of U.S. patentapplication Ser. No. 17/711,934, filed on Apr. 1, 2022, which is aContinuation Application of International Application No.PCT/KR2020/013475, filed on Oct. 5, 2020, which claims the benefit ofand priority to U.S. Provisional Application No. 62/911,120, filed onOct. 4, 2019 and U.S. Provisional Application No. 62/933,229, filed onNov. 8, 2019, the contents of which are all hereby incorporated byreference herein in their entirety.

TECHNICAL FIELD

Embodiments of the present disclosure relate to a wireless communicationsystem.

BACKGROUND ART

Wireless access systems have been widely deployed to provide varioustypes of communication services such as voice or data. In general, awireless access system is a multiple access system that supportscommunication of multiple users by sharing available system resources (abandwidth, transmission power, etc.) among them. For example, multipleaccess systems include a code division multiple access (CDMA) system, afrequency division multiple access (FDMA) system, a time divisionmultiple access (TDMA) system, an orthogonal frequency division multipleaccess (OFDMA) system, and a single carrier frequency division multipleaccess (SC-FDMA) system.

DISCLOSURE Technical Problem

Various embodiments may provide a method of transmitting and receiving asignal in a wireless communication system and apparatus for supportingthe same.

Various embodiments may provide a method for a 2-step random accesschannel (RACH) procedure in a wireless communication system andapparatus for supporting the same.

Various embodiments may provide a method of configuring a message Aphysical uplink shared channel (PUSCH) demodulation reference signal(DMRS) in a wireless communication system and apparatus for supportingthe same.

Various embodiments may provide a method of mapping a preamble to aPUSCH occasion in a wireless communication system and apparatus forsupporting the same.

It will be appreciated by persons skilled in the art that the objectsthat could be achieved with the various embodiments of the presentdisclosure are not limited to what has been particularly describedhereinabove and the above and other objects that the various embodimentsof the present disclosure could achieve will be more clearly understoodfrom the following detailed description.

Technical Solution

Various embodiments may provide a method of transmitting and receiving asignal in a wireless communication system and apparatus for supportingthe same.

According to various embodiments, a method performed by a user equipment(UE) in a wireless communication system may be provided.

According to various embodiments, the method may include: obtaining amessage A including a physical random access channel (PRACH) preambleand a physical uplink shared channel (PUSCH); and transmitting themessage A.

According to various embodiments, the PUSCH may be transmitted based onreceived information related to a PUSCH configuration for the message A.

According to various embodiments, based on that the information relatedto the PUSCH configuration includes information related to indication ofa code division multiplexing (CDM) group for a demodulation referencesignal (DMRS) for the PUSCH, the CDM group may be configured as a groupindicated by the information related to the indication of the CDM groupof two predetermined groups.

According to various embodiments, based on that the information relatedto the PUSCH configuration does not include the information related tothe indication of the CDM group, the CDM group may be configured as thetwo predetermined groups.

According to various embodiments, a number of ports for the DMRS may bedetermined in a set of {1, 2, 4}.

According to various embodiments, based on that transform precoding forthe PUSCH is disabled: two different identifiers (IDs) related toidentifying a sequence for initialization of a pseudo-random sequencegenerator related to sequence generation of the DMRS may be obtainedbased on two different higher layer parameters, respectively.

According to various embodiments, a scrambling ID (SCID) related toidentifying indices of the two different IDs may be determined based onthe PRACH preamble.

According to various embodiments, based on the transform precoding isenabled, one ID related to identifying the sequence for theinitialization of the pseudo-random sequence generator may be obtainedbased on a higher layer parameter.

According to various embodiments, the PRACH preamble may be obtainedfrom among a plurality of PRACH preambles, and

According to various embodiments, the SCID may be determined based onmapping between the plurality of preambles and a PUSCH occasion fortransmitting the PUSCH.

According to various embodiments, an apparatus configured to operate ina wireless communication system may be provided.

According to various embodiments, the apparatus may include: a memory;and at least one processor connected to the memory.

According to various embodiments, the at least one processor may beconfigured to: obtain a message A including a PRACH preamble and aPUSCH; and transmit the message A.

According to various embodiments, the PUSCH may be transmitted based onreceived information related to a PUSCH configuration for the message A.

According to various embodiments, based on that the information relatedto the PUSCH configuration includes information related to indication ofa CDM group for a DMRS for the PUSCH, the CDM group may be configured asa group indicated by the information related to the indication of theCDM group of two predetermined groups.

According to various embodiments, based on that the information relatedto the PUSCH configuration does not include the information related tothe indication of the CDM group, the CDM group may be configured as thetwo predetermined groups.

According to various embodiments, a number of ports for the DMRS may bedetermined in a set of {1, 2, 4}.

According to various embodiments, based on that transform precoding forthe PUSCH is disabled: two different identifiers (IDs) related toidentifying a sequence for initialization of a pseudo-random sequencegenerator related to sequence generation of the DMRS may be obtainedbased on two different higher layer parameters, respectively.

According to various embodiments, a scrambling ID (SCID) related toidentifying indices of the two different IDs may be determined based onthe PRACH preamble.

According to various embodiments, the apparatus may communicate with atleast one of a mobile terminal, a network, or an autonomous drivingvehicle other than a vehicle including the apparatus.

According to various embodiments, a method performed by a base station(BS) in a wireless communication system may be provided.

According to various embodiments, the method may include: receiving amessage A; and obtaining a PRACH preamble and a PUSCH based on themessage A.

According to various embodiments, the PUSCH may be obtained based ontransmitted information related to a PUSCH configuration for the messageA.

According to various embodiments, based on that the information relatedto the PUSCH configuration includes information related to indication ofa CDM group for a DMRS for the PUSCH, the CDM group may be configured asa group indicated by the information related to the indication of theCDM group of two predetermined groups.

According to various embodiments, an apparatus configured to operate ina wireless communication system may be provided.

According to various embodiments, the apparatus may include: a memory;and at least one processor connected to the memory.

According to various embodiments, the at least one processor may beconfigured to: receive a message A; and obtain a PRACH preamble and aPUSCH based on the message A.

According to various embodiments, the PUSCH may be obtained based ontransmitted information related to a PUSCH configuration for the messageA.

According to various embodiments, based on that the information relatedto the PUSCH configuration includes information related to indication ofa CDM group for a DMRS for the PUSCH, the CDM group may be configured asa group indicated by the information related to the indication of theCDM group of two predetermined groups.

According to various embodiments, an apparatus configured to operate ina wireless communication system may be provided.

According to various embodiments, the apparatus may include: at leastone processor; obtaining a message A including a PRACH preamble and aPUSCH; and transmitting the message A.

According to various embodiments, the PUSCH may be transmitted based onreceived information related to a PUSCH configuration for the message A.

According to various embodiments, based on that the information relatedto the PUSCH configuration includes information related to indication ofa CDM group for a DMRS for the PUSCH, the CDM group may be configured asa group indicated by the information related to the indication of theCDM group of two predetermined groups.

According to various embodiments, a processor-readable medium configuredto store one or more instructions that cause at least one processor toperform a method may be provided.

According to various embodiments, the method may include: obtaining amessage A including a PRACH preamble and a PUSCH; and transmitting themessage A.

According to various embodiments, the PUSCH may be transmitted based onreceived information related to a PUSCH configuration for the message A.

According to various embodiments, based on that the information relatedto the PUSCH configuration includes information related to indication ofa CDM group for a DMRS for the PUSCH, the CDM group may be configured asa group indicated by the information related to the indication of theCDM group of two predetermined groups.

It will be appreciated by persons skilled in the art that the objectsthat could be achieved with the present disclosure are not limited towhat has been particularly described hereinabove and the above and otherobjects that the present disclosure could achieve will be more clearlyunderstood from the following detailed description.

Advantageous Effects

According to various embodiments, signals may be effectively transmittedand received in a wireless communication system.

According to various embodiments, message A physical uplink sharedchannel (PUSCH) demodulation reference signal (DMRS) resources (e.g.,DMRS ports/sequences, etc.) may be used efficiently

According to various embodiments, preambles may be used efficiently.

It will be appreciated by persons skilled in the art that that theeffects that can be achieved through the various embodiments of thepresent disclosure are not limited to those described above and otheradvantageous effects of the various embodiments of the presentdisclosure will be more clearly understood from the following detaileddescription. That is, unintended effects according to implementation ofthe present disclosure may be derived by those skilled in the art fromthe various embodiments of the present disclosure.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the various embodiments of the present disclosure,provide the various embodiments of the present disclosure together withdetail explanation. Yet, a technical characteristic the variousembodiments of the present disclosure is not limited to a specificdrawing. Characteristics disclosed in each of the drawings are combinedwith each other to configure a new embodiment. Reference numerals ineach drawing correspond to structural elements.

FIG. 1 is a diagram illustrating physical channels and a signaltransmission method using the physical channels, which may be used invarious embodiments of the present disclosure.

FIG. 2 is a diagram illustrating a radio frame structure in a new radioaccess technology (NR) system to which various embodiments of thepresent disclosure are applicable.

FIG. 3 is a diagram illustrating a slot structure in a new radio (NR)system to which various embodiments of the present disclosure areapplicable.

FIG. 4 is a diagram illustrating mapping of physical channels in a slot,to which various embodiments are applicable.

FIG. 5 is a diagram illustrating the structure of a synchronizationsignal block (SSB) to which various embodiments of the presentdisclosure are applicable.

FIG. 6 is a diagram illustrating an exemplary SSB transmission method towhich various embodiments of the present disclosure are applicable.

FIG. 7 illustrates acquisition of DL time synchronization information ata user equipment (UE) which various embodiments of the presentdisclosure are applicable.

FIG. 8 illustrates a system information (SI) acquisition procedure whichvarious embodiments of the present disclosure are applicable.

FIG. 9 is a diagram illustrating exemplary multi-beam transmission towhich various embodiments are applicable.

FIG. 10 is a diagram illustrating a method of indicating an actuallytransmitted SSB (SSB_tx) to which various embodiments are applicable.

FIG. 11 is a diagram illustrating an exemplary 4-step random accesschannel (RACH) procedure to which various embodiments of the presentdisclosure are applicable.

FIG. 12 is a diagram illustrating an exemplary 2-step RACH procedure towhich various embodiments of the present disclosure are applicable.

FIG. 13 is a diagram illustrating an exemplary contention-free RACHprocedure to which various embodiments of the present disclosure areapplicable.

FIG. 14 is a diagram illustrating transmission of SSBs and physicalrandom access channel (PRACH) resources linked to the SSBs according tovarious embodiments of the present disclosure.

FIG. 15 is a diagram illustrating transmission of SSBs and PRACHresources linked to the SSBs according to various embodiments of thepresent disclosure.

FIG. 16 is a diagram illustrating an exemplary RACH occasionconfiguration to which various embodiments of the present disclosure areapplicable.

FIG. 17 is a diagram schematically illustrating a method of operating aUE and a based station (BS) according to various embodiments of thepresent disclosure.

FIG. 18 is a diagram schematically illustrating a method of operating aUE according to various embodiments.

FIG. 19 is a diagram schematically illustrating a method of operating aBS according to various embodiments.

FIG. 20 is a diagram illustrating an exemplary resource configurationfor message A (MsgA) according to various embodiments.

FIG. 21 is a diagram illustrating an exemplary MsgA configurationaccording to various embodiments.

FIG. 22 is a diagram illustrating an exemplary MsgA configurationaccording to various embodiments.

FIG. 23 is a diagram illustrating exemplary time-domain locations for aMsgA RACH and a MsgA physical uplink shared channel (PUSCH) according tovarious embodiments.

FIG. 24 is a diagram schematically illustrating a method of operating aUE and a BS according to various embodiments.

FIG. 25 is a flowchart illustrating a method of operating a UE accordingto various embodiments.

FIG. 26 is a flowchart illustrating a method of operating a BS accordingto various embodiments.

FIG. 27 is a diagram illustrating devices that implement variousembodiments of the present disclosure.

FIG. 28 illustrates an exemplary communication system to which variousembodiments of the present disclosure are applied.

FIG. 29 illustrates exemplary wireless devices to which variousembodiments of the present disclosure are applicable.

FIG. 30 illustrates other exemplary wireless devices to which variousembodiments of the present disclosure are applied.

FIG. 31 illustrates an exemplary portable device to which variousembodiments of the present disclosure are applied.

FIG. 32 illustrates an exemplary vehicle or autonomous driving vehicleto which various embodiments of the present disclosure.

MODE FOR DISCLOSURE

Various embodiments are applicable to a variety of wireless accesstechnologies such as code division multiple access (CDMA), frequencydivision multiple access (FDMA), time division multiple access (TDMA),orthogonal frequency division multiple access (OFDMA), and singlecarrier frequency division multiple access (SC-FDMA). CDMA can beimplemented as a radio technology such as Universal Terrestrial RadioAccess (UTRA) or CDMA2000. TDMA can be implemented as a radio technologysuch as Global System for Mobile communications (GSM)/General PacketRadio Service (GPRS)/Enhanced Data Rates for GSM Evolution (EDGE). OFDMAcan be implemented as a radio technology such as Institute of Electricaland Electronics Engineers (IEEE) 802.11 (Wireless Fidelity (Wi-Fi)),IEEE 802.16 (Worldwide interoperability for Microwave Access (WiMAX)),IEEE 802.20, and Evolved UTRA (E-UTRA). UTRA is a part of UniversalMobile Telecommunications System (UMTS). 3rd Generation PartnershipProject (3GPP) Long Term Evolution (LTE) is part of Evolved UMTS(E-UMTS) using E-UTRA, and LTE-Advanced (A) is an evolved version of3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is anevolved version of 3GPP LTE/LTE-A.

Various embodiments are described in the context of a 3GPP communicationsystem (e.g., including LTE, NR, 6G, and next-generation wirelesscommunication systems) for clarity of description, to which thetechnical spirit of the various embodiments is not limited. For thebackground art, terms, and abbreviations used in the description of thevarious embodiments, refer to the technical specifications publishedbefore the present disclosure. For example, the documents of 3GPP TS36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.300, 3GPP TS 36.321,3GPP TS 36.331, 3GPP TS 36.355, 3GPP TS 36.455, 3GPP TS 37.355, 3GPP TS37.455, 3GPP TS 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS 38.214,3GPP TS 38.215, 3GPP TS 38.300, 3GPP TS 38.321, 3GPP TS 38.331, 3GPP TS38.355, 3GPP TS 38.455, and so on may be referred to.

1. 3GPP System 1.1. Physical Channels and Signal Transmission andReception

In a wireless access system, a UE receives information from a BS on a DLand transmits information to the BS on a UL. The information transmittedand received between the UE and the BS includes general data informationand various types of control information. There are many physicalchannels according to the types/usages of information transmitted andreceived between the BS and the UE.

FIG. 1 is a diagram illustrating physical channels and a signaltransmission method using the physical channels, which may be used invarious embodiments of the present disclosure.

When a UE is powered on or enters a new cell, the UE performs initialcell search (S11). The initial cell search involves acquisition ofsynchronization to a BS. Specifically, the UE synchronizes its timing tothe BS and acquires information such as a cell identifier (ID) byreceiving a primary synchronization channel (P-SCH) and a secondarysynchronization channel (S-SCH) from the BS.

Then the UE may acquire information broadcast in the cell by receiving aphysical broadcast channel (PBCH) from the BS.

During the initial cell search, the UE may monitor a DL channel state byreceiving a downlink reference signal (DL RS).

After the initial cell search, the UE may acquire more detailed systeminformation by receiving a physical downlink control channel (PDCCH) andreceiving on a physical downlink shared channel (PDSCH) based oninformation of the PDCCH (S12).

Subsequently, to complete connection to the BS, the UE may perform arandom access procedure with the BS (S13 to S16). In the random accessprocedure, the UE may transmit a preamble on a physical random accesschannel (PRACH) (S13) and may receive a PDCCH and a random accessresponse (RAR) for the preamble on a PDSCH associated with the PDCCH(S14). The UE may transmit a PUSCH by using scheduling information inthe RAR (S15), and perform a contention resolution procedure includingreception of a PDCCH signal and a PDSCH signal corresponding to thePDCCH signal (S16).

When the random access procedure is performed in two steps, steps S13and S15 may be performed in one operation for a UE transmission, andsteps S14 and S16 may be performed in one operation for a BStransmission.

After the above procedure, the UE may receive a PDCCH and/or a PDSCHfrom the BS (S17) and transmit a physical uplink shared channel (PUSCH)and/or a physical uplink control channel (PUCCH) to the BS (S18), in ageneral UL/DL signal transmission procedure.

Control information that the UE transmits to the BS is genericallycalled UCI. The UCI includes a hybrid automatic repeat and requestacknowledgement/negative acknowledgement (HARQ-ACK/NACK), a schedulingrequest (SR), a channel quality indicator (CQI), a precoding matrixindex (PMI), a rank indicator (RI), etc.

In general, UCI is transmitted periodically on a PUCCH. However, ifcontrol information and traffic data should be transmittedsimultaneously, the control information and traffic data may betransmitted on a PUSCH. In addition, the UCI may be transmittedaperiodically on the PUSCH, upon receipt of a request/command from anetwork.

1.2. Radio Frame Structures

FIG. 2 is a diagram illustrating a radio frame structure in an NR systemto which various embodiments of the present disclosure are applicable.

The NR system may support multiple numerologies. A numerology may bedefined by a subcarrier spacing (SCS) and a cyclic prefix (CP) overhead.Multiple SCSs may be derived by scaling a default SCS by an integer N(or μ). Further, even though it is assumed that a very small SCS is notused in a very high carrier frequency, a numerology to be used may beselected independently of the frequency band of a cell. Further, the NRsystem may support various frame structures according to multiplenumerologies.

Now, a description will be given of OFUM numerologies and framestructures which may be considered for the NR system. Multiple OFUMnumerologies supported by the NR system may be defined as listed inTable 1. For a bandwidth part (BWP), μ and a CP are obtained from RRCparameters provided by the BS.

TABLE 1 μ Δf = 2^(μ) · 15 [kHz] Cyclic prefix 0 15 Normal 1 30 Normal 260 Normal, Extended 3 120 Normal 4 240 Normal

In NR, multiple numerologies (e.g., SCSs) are supported to support avariety of 5G services. For example, a wide area in cellular bands issupported for an SCS of 15 kHz, a dense-urban area, a lower latency, anda wider carrier bandwidth are supported for an SCS of 30 kHz/60 kHz, anda larger bandwidth than 24.25 GHz is supported for an SCS of 60 kHz ormore, to overcome phase noise.

An NR frequency band is defined by two types of frequency ranges, FR1and FR2. FR1 may be a sub-6 GHz range, and FR2 may be an above-6 GHzrange, that is, a millimeter wave (mmWave) band.

Table 2 below defines the NR frequency band, by way of example.

TABLE 2 Frequency range designation Corresponding frequency rangeSubcarrier Spacing FR1  410 MHz-7125 MHz  15, 30, 60 kHz FR2 24250MHz-52600 MHZ 60, 120, 240 kHz 

Regarding a frame structure in the NR system, the time-domain sizes ofvarious fields are represented as multiples of a basic time unit for NR,T_(c)=1/(Δf_(max)*N_(f)) where Δf_(max)=480*10³ Hz and a value N_(f)related to a fast Fourier transform (FFT) size or an inverse fastFourier transform (IFFT) size is given as N_(f)=4096. T_(c) and T_(s)which is an LTE-based time unit and sampling time, given as T_(s)=1/((15kHz)*2048) are placed in the following relationship: T_(s)/T_(c)=64. DLand UL transmissions are organized into (radio) frames each having aduration of T_(f)=(Δf_(max)*N_(f)/100)*T_(c)=10 ms. Each radio frameincludes 10 subframes each having a duration ofT_(sf)=(Δf_(max)*N_(f)/1000)*T_(c)=1 ms. There may exist one set offrames for UL and one set of frames for DL. For a numerology μ, slotsare numbered with n^(μ) _(s)∈{0, . . . , N^(slot,μ) _(subframe)−1} in anincreasing order in a subframe, and with n^(μ) _(s,f)∈{0, . . . ,N^(slot,μ) _(frame)−1} in an increasing order in a radio frame. One slotincludes N^(μ) _(symb) consecutive OFDM symbols, and N^(μ) _(symb)depends on a CP. The start of a slot n^(μ) _(s) in a subframe is alignedin time with the start of an OFDM symbol n^(μ) _(s)*N^(μ) _(symb) in thesame subframe.

Table 3 lists the number of symbols per slot, the number of slots perframe, and the number of slots per subframe, for each SCS in a normal CPcase, and Table 4 lists the number of symbols per slot, the number ofslots per frame, and the number of slots per subframe, for each SCS inan extended CP case.

TABLE 3 μ N_(symb) ^(slot) N_(slot) ^(frame,μ) N_(slot) ^(subframe,μ) 014 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160  16 

TABLE 4 μ N_(symb) ^(slot) N_(slot) ^(frame,μ) N_(slot) ^(subframe,μ) 212 40 4

In the above tables, N^(slot) _(symb) represents the number of symbolsin a slot, N^(frame,μ) _(slot) represents the number of slots in aframe, and N^(subframe,μ) _(slot) represents the number of slots in asubframe.

In the NR system to which various embodiments of the present disclosureare applicable, different OFDM(A) numerologies (e.g., SCSs, CP lengths,and so on) may be configured for a plurality of cells which areaggregated for one UE. Accordingly, the (absolute time) period of a timeresource including the same number of symbols (e.g., a subframe (SF), aslot, or a TTI) (generically referred to as a time unit (TU), forconvenience) may be configured differently for the aggregated cells.

FIG. 2 illustrates an example with μ=2 (i.e., an SCS of 60 kHz), inwhich referring to Table 6, one subframe may include four slots. Onesubframe={1, 2, 4} slots in FIG. 7 , which is exemplary, and the numberof slot(s) which may be included in one subframe is defined as listed inTable 3 or Table 4.

Further, a mini-slot may include 2, 4 or 7 symbols, fewer symbols than2, or more symbols than 7.

FIG. 3 is a diagram illustrating a slot structure in an NR system towhich various embodiments of the present disclosure are applicable.

Referring FIG. 3 , one slot includes a plurality of symbols in the timedomain. For example, one slot includes 7 symbols in a normal CP case and6 symbols in an extended CP case.

A carrier includes a plurality of subcarriers in the frequency domain.An RB is defined by a plurality of (e.g., 12) consecutive subcarriers inthe frequency domain.

A BWP, which is defined by a plurality of consecutive (P)RBs in thefrequency domain, may correspond to one numerology (e.g., SCS, CPlength, and so on).

A carrier may include up to N (e.g., 5) BWPs. Data communication may beconducted in an activated BWP, and only one BWP may be activated for oneUE. In a resource grid, each element is referred to as an RE, to whichone complex symbol may be mapped.

FIG. 4 is a diagram illustrating exemplary mapping of physical channelsin a slot, to which various embodiments are applicable.

One slot may include all of a DL control channel, DL or UL data, and aUL control channel. For example, the first N symbols of a slot may beused to transmit a DL control channel (hereinafter, referred to as a DLcontrol region), and the last M symbols of the slot may be used totransmit a UL control channel (hereinafter, referred to as a UL controlregion). Each of N and M is an integer equal to or larger than 0. Aresource area (hereinafter, referred to as a data region) between the DLcontrol region and the UL control region may be used to transmit DL dataor UL data. There may be a time gap for DL-to-UL or UL-to-DL switchingbetween a control region and a data region. A PDCCH may be transmittedin the DL control region, and a PDSCH may be transmitted in the DL dataregion. Some symbols at a DL-to-UL switching time in the slot may beused as the time gap.

1.3. Channel Structures 1.3.1. DL Channel Structures

The BS transmits related signals to the UE on DL channels as describedbelow, and the UE receives the related signals from the BS on the DLchannels.

1.3.1.1. Physical Downlink Shared Channel (PDSCH)

The PDSCH conveys DL data (e.g., DL-shared channel transport block(DL-SCH TB)) and uses a modulation scheme such as quadrature phase shiftkeying (QPSK), 16-ary quadrature amplitude modulation (16QAM), 64QAM, or256QAM. A TB is encoded into a codeword. The PDSCH may deliver up to twocodewords. Scrambling and modulation mapping are performed on a codewordbasis, and modulation symbols generated from each codeword are mapped toone or more layers (layer mapping). Each layer together with ademodulation reference signal (DMRS) is mapped to resources, generatedas an OFDM symbol signal, and transmitted through a correspondingantenna port.

1.3.1.2. Physical Downlink Control Channel (PDCCH)

The PDCCH may deliver downlink control information (DCI), for example,DL data scheduling information, UL data scheduling information, and soon. The PUCCH may deliver uplink control information (UCI), for example,an ACK/NACK information for DL data, channel state information (CSI), ascheduling request (SR), and so on.

The PDCCH carries DCI and is modulated in QPSK. One PDCCH includes 1, 2,4, 8, or 16 control channel elements (CCEs) according to an aggregationlevel (AL). One CCE includes 6 resource element groups (REGs). One REGis defined by one OFDM symbol by one (P)RB.

The PDCCH is transmitted in a control resource set (CORESET). A CORESETis defined as a set of REGs having a given numerology (e.g., SCS, CPlength, and so on). A plurality of CORESETs for one UE may overlap witheach other in the time/frequency domain. A CORESET may be configured bysystem information (e.g., a master information block (MIB)) or byUE-specific higher layer (RRC) signaling. Specifically, the number ofRBs and the number of symbols (up to 3 symbols) included in a CORESETmay be configured by higher-layer signaling.

The UE acquires DCI delivered on a PDCCH by decoding (so-called blinddecoding) a set of PDCCH candidates. A set of PDCCH candidates decodedby a UE are defined as a PDCCH search space set. A search space set maybe a common search space (CSS) or a UE-specific search space (USS). TheUE may acquire DCI by monitoring PDCCH candidates in one or more searchspace sets configured by an MIB or higher-layer signaling. Each CORESETconfiguration is associated with one or more search space sets, and eachsearch space set is associated with one CORESET configuration.

Table 5 lists exemplary features of the respective search space types.

TABLE 5 Search Type Space RNTI Use Case Type0-PDCCH Common SI-RNTI on aprimary cell SIB Decoding Type0A-PDCCH Common SI-RNTI on a primary cellSIB Decoding Type1-PDCCH Common RA-RNTI or TC-RNTI on Msg2, Msg4 aprimary cell decoding in RACH Type2-PDCCH Common P-RNTI on a primarycell Paging Decoding Type3-PDCCH Common INT-RNTI, SFI-RNTI,TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS- RNTI, C-RNTI, MCS-C-RNTI, orCS-RNTI(s) UE C-RNTI, or MCS-C-RNTI, User specific Specific orCS-RNTI(s) PDSCH decoding

Table 6 lists exemplary DCI formats transmitted on the PDCCH.

TABLE 6 DCI format Usage 0_0 Scheduling of PUSCH in one cell 0_1Scheduling of PUSCH in one cell 1_0 Scheduling of PDSCH in one cell 1_1Scheduling of PDSCH in one cell 2_0 Notifying a group of UEs of the slotformat 2_1 Notifying a group of UEs of the PRB(s) and OFDM symbol(s)where UE may assume no transmission is intended for the UE 2_2Transmission of TPC commands for PUCCH and PUSCH 2_3 Transmission of agroup of TPC commands for SRS transmissions by one or more UEs

DCI format 0_0 may be used to schedule a TB-based (or TB-level) PUSCH,and DCI format 0_1 may be used to schedule a TB-based (or TB-level)PUSCH or a code block group (CBG)-based (or CBG-level) PUSCH. DCI format1_0 may be used to schedule a TB-based (or TB-level) PDSCH, and DCIformat 1_1 may be used to schedule a TB-based (or TB-level) PDSCH or aCBG-based (or CBG-level) PDSCH. DCI format 2_0 is used to deliverdynamic slot format information (e.g., a dynamic slot format indicator(SFI)) to the UE, and DCI format 2_1 is used to deliver DL preemptioninformation to the UE. DCI format 2_0 and/or DCI format 2_1 may bedelivered to the UEs of a group on a group common PDCCH (GC-PDCCH) whichis a PDCCH directed to a group of UEs.

1.3.2. UL Channel Structures

The UE transmits related signals on later-described UL channels to theBS, and the BS receives the related signals on the UL channels from theUE.

1.3.2.1. Physical Uplink Shared Channel (PUSCH)

The PUSCH delivers UL data (e.g., a UL-shared channel transport block(UL-SCH TB)) and/or UCI, in cyclic prefix-orthogonal frequency divisionmultiplexing (CP-OFDM) waveforms or discrete Fouriertransform-spread-orthogonal division multiplexing (DFT-s-OFDM)waveforms. If the PUSCH is transmitted in DFT-s-OFDM waveforms, the UEtransmits the PUSCH by applying transform precoding. For example, iftransform precoding is impossible (e.g., transform precoding isdisabled), the UE may transmit the PUSCH in CP-OFDM waveforms, and iftransform precoding is possible (e.g., transform precoding is enabled),the UE may transmit the PUSCH in CP-OFDM waveforms or DFT-s-OFDMwaveforms. The PUSCH transmission may be scheduled dynamically by a ULgrant in DCI or semi-statically by higher-layer signaling (e.g., RRCsignaling) (and/or layer 1 (L1) signaling (e.g., a PDCCH)) (a configuredgrant). The PUSCH transmission may be performed in a codebook-based ornon-codebook-based manner.

1.3.2.2. Physical Uplink Control Channel (PUCCH)

The PUCCH delivers UCI, an HARQ-ACK, and/or an SR and is classified as ashort PUCCH or a long PUCCH according to the transmission duration ofthe PUCCH. Table 7 lists exemplary PUCCH formats.

TABLE 7 Length in OFDM PUCCH symbols Number format N_(symb) ^(PUCCH) ofbits Usage Etc 0 1-2 ≤2 HARQ, SR Sequence selection 1  4-14 ≤2 HARQ,[SR] Sequence modulation 2 1-2 >2 HARQ, CSI, [SR] CP-OFDM 3  4-14 >2HARQ, CSI, [SR] DFT-s-OFDM (no UE multiplexing) 4  4-14 >2 HARQ, CSI,[SR] DFT-s-OFDM (Pre DFT OCC)

PUCCH format 0 conveys UCI of up to 2 bits and is mapped in asequence-based manner, for transmission. Specifically, the UE transmitsspecific UCI to the BS by transmitting one of a plurality of sequenceson a PUCCH of PUCCH format 0. Only when the UE transmits a positive SR,the UE transmits the PUCCH of PUCCH format 0 in a PUCCH resource for acorresponding SR configuration.

PUCCH format 1 conveys UCI of up to 2 bits and modulation symbols of theUCI are spread with an OCC (which is configured differently whetherfrequency hopping is performed) in the time domain. The DMRS istransmitted in a symbol in which a modulation symbol is not transmitted(i.e., transmitted in time division multiplexing (TDM)).

PUCCH format 2 conveys UCI of more than 2 bits and modulation symbols ofthe DCI are transmitted in frequency division multiplexing (FDM) withthe DMRS. The DMRS is located in symbols #1, #4, #7, and #10 of a givenRB with a density of ⅓. A pseudo noise (PN) sequence is used for a DMRSsequence. For 1-symbol PUCCH format 2, frequency hopping may beactivated.

PUCCH format 3 does not support UE multiplexing in the same PRBS, andconveys UCI of more than 2 bits. In other words, PUCCH resources ofPUCCH format 3 do not include an OCC. Modulation symbols are transmittedin TDM with the DMRS.

PUCCH format 4 supports multiplexing of up to 4 UEs in the same PRBS,and conveys UCI of more than 2 bits. In other words, PUCCH resources ofPUCCH format 3 includes an OCC. Modulation symbols are transmitted inTDM with the DMRS.

1.4. Bandwidth Part (BWP)

The NR system may support up to 400 MHz for each carrier. If the UEalways turns on a radio frequency (RF) module for all carriers whileoperating on such a wideband carrier, the battery consumption of the UEmay increase. Considering multiple use cases operating on one widebandcarrier (e.g., enhanced mobile broadband (eMBB), ultra-reliable andlow-latency communication (URLLC), massive machine type communications(mMTC), vehicle-to-everything (V2X), etc.), a different numerology(e.g., SCS) may be supported for each frequency band of the carrier.Further, considering that each UE may have a different capabilityregarding the maximum bandwidth, the BS may instruct the UE to operateonly in a partial bandwidth rather than the whole bandwidth of thewideband carrier. The partial bandwidth is referred to as a BWP. The BWPis a subset of contiguous common RBs defined for numerology μi in BWP iof a carrier in the frequency domain, and one numerology (e.g., SCS, CPlength, and/or slot/mini-slot duration) may be configured for each BWP.

The BS may configure one or more BWPs in one carrier configured to theUE. Alternatively, if UEs are concentrated in a specific BWP, the BS maymove some UEs to another BWP for load balancing. For frequency-domaininter-cell interference cancellation between neighboring cells, the BSmay configure BWPs on both sides of a cell except for some centralspectra in the whole bandwidth within the same slot. That is, the BS mayconfigure at least one DL/UL BWP for the UE associated with a widebandcarrier, activate at least one DL/UL BWP among DL/UL BWP(s) configuredat a specific time (by L1 signaling which is a physical-layer controlsignal, a MAC control element (CE) which is a MAC-layer control signal,or RRC signaling), and instruct the UE to switch to another configuredDL/UL BWP (by L1 signaling, a MAC CE, or RRC signaling). Alternatively,the BS may configure a timer and switch the UE to a predetermined DL/ULBWP upon expiration of the timer. In particular, an activated DL/UL BWPis referred to as an active DL/UL BWP. While performing initial accessor before setting up an RRC connection, the UE may not receive any DL/ULBWP configurations. A DL/UL BWP that the UE assumes in this situation isreferred to as an initial active DL/UL BWP.

1.5. Synchronization Signal Block (SSB) Transmission and RelatedOperation

FIG. 5 is a diagram illustrating the structure of a synchronizationsignal block (SSB) to which various embodiments of the presentdisclosure are applicable.

A UE may perform cell search, system information acquisition, beamalignment for initial access, DL measurement, and so on based on an SSB.The term SSB is interchangeably used with synchronizationsignal/physical broadcast channel (SS/PBCH) block.

Referring to FIG. 5 , the SSB to which various embodiments of thepresent disclosure are applicable may include 20 RBs in four consecutiveOFDM symbols. Further, the SSB may include a PSS, an SSS, and a PBCH,and the UE may perform cell search, system information acquisition, beamalignment for initial access, DL measurement, and so on based on theSSB.

Each of the PSS and the SSS includes one OFDM symbol by 127 subcarriers,and the PBCH includes three OFDM symbols by 576 subcarriers. Polarcoding and QPSK are applied to the PBCH. The PBCH includes data REs andDMRS REs in every OFDM symbol. There are three DMRS REs per RB, withthree data REs between every two adjacent DMRS REs.

Cell Search

Cell search refers to a procedure in which the UE acquirestime/frequency synchronization of a cell and detects a cell ID (e.g.,physical layer cell ID (PCID)) of the cell. The PSS may be used todetect a cell ID within a cell ID group, and the SSS may be used todetect the cell ID group. The PBCH may be used in detecting an SSB(time) index and a half-frame.

The cell search procedure of the UE may be summarized as described inTable 8 below.

TABLE 8 Type of Signals Operations 1^(st) step PSS SS/PBCH block (SSB)symbol timing acquisition Cell ID detection within a cell ID group (3hypothesis) 2^(nd) Step SSS Cell ID group detection (336 hypothesis)3^(rd) Step PBCH DMRS SSB index and Half frame (HF) index (Slot andframe boundary detection) 4^(th) Step PBCH Time information (80 ms,System Frame Number (SFN), SSB index, HF) Remaining Minimum SystemInformation (RMSI) Control resource set (CORESET)/Search spaceconfiguration 5^(th) Step PDCCH and Cell access information PDSCH RACHconfiguration

There are 336 cell ID groups each including three cell IDs. There are1008 cell IDs in total. Information about a cell ID group to which thecell ID of a cell belongs may be provided/obtained through the SSS ofthe cell, and information about the cell ID among 336 cells in the cellID may be provided/obtained through the PSS.

FIG. 6 is a diagram illustrating an exemplary SSB transmission method towhich various embodiments of the present disclosure are applicable.

Referring to FIG. 6 , the SSB is periodically transmitted according toan SSB periodicity. A default SSB periodicity assumed by the UE duringinitial cell search is defined as 20 ms. After the cell access, the SSBperiodicity may be set to one of {5 ms, 10 ms, 20 ms, 40 ms, 80 ms, 160ms} by the network (e.g., the BS). An SSB burst set is configured at thebeginning of an SSB period. The SSB burst set may be configured with a5-ms time window (i.e., half-frame), and an SSB may be repeatedlytransmitted up to L times within the SS burst set. The maximum number oftransmissions of the SSB, L may be given according to the frequency bandof a carrier as follows. One slot includes up to two SSBs.

-   -   For frequency range up to 3 GHz, L=4    -   For frequency range from 3 GHz to 6 GHz, L=8    -   For frequency range from 6 GHz to 52.6 GHz, L=64

The time position of an SSB candidate in the SS burst set may be definedaccording to an SCS as follows. The time positions of SSB candidates areindexed as (SSB indexes) 0 to L−1 in time order within the SSB burst set(i.e., half-frame). In the description of various embodiments of thepresent disclosure, the candidate SSB and the SSB candidate may beinterchangeably used.

-   -   Case A: 15-kHz SCS: The indexes of the first symbols of        candidate SSBs are given as {2, 8}+14*n        -   for operation without shared spectrum channel access (e.g.,            L-band and LCell): where n=0, 1 for a carrier frequency            equal to or less than 3 GHz and n=0, 1, 2, 3 for a carrier            frequency of 3 GHz to 6 GHz.            -   For operation with shared spectrum channel access (e.g.,                U-band and UCell): where n=0, 1, 2, 3, 4.    -   Case B: 30-kHz SCS: The indexes of the first symbols of        candidate SSBs are given as {4, 8, 16, 20}+28*n where n=0 for a        carrier frequency equal to or lower than 3 GHz, and n=0, 1 for a        carrier frequency of 3 GHz to 6 GHz.    -   Case C: 30-kHz SCS: The indexes of the first symbols of        candidate SSBs are given as {2, 8}+14*n        -   For operation without shared spectrum channel access: (1) In            the case of a paired spectrum operation where n=0, if for a            carrier frequency equal to or less than 3 GHz and n=0, 1, 2,            3 for a carrier frequency within FR1 and greater than 3            GHz. (2) In the case of a non-paired spectrum operation,            where n=0, 1 for a carrier frequency equal to or less than            2.4 GHz and n=0, 1, 2, 3 for a carrier frequency within FR1            and greater than 2.4 GHz.        -   For operation with shared spectrum channel access: where            n=0, 1, 2, 3, 4, 6, 7, 8, 9.    -   Case D: 120-kHz SCS: The indexes of the first symbols of        candidate SSBs are given as {4, 8, 16, 20}+28*n where n=0, 1, 2,        3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18 for a carrier        frequency above 6 GHz.    -   Case E: 240-kHz SCS: The indexes of the first symbols of        candidate SSBs are given as {8, 12, 16, 20, 32, 36, 40, 44}+56*n        where n=0, 1, 2, 3, 5, 6, 7, 8 for a carrier frequency above 6        GHz.

Synchronization Procedure

FIG. 7 illustrates acquisition of DL time synchronization information ata UE which various embodiments of the present disclosure are applicable.

The UE may obtain DL synchronization by detecting an SSB. The UE mayidentify the structure of an SSB burst set based on the index of thedetected SSB and thus detect a symbol, slot, or half-frame boundary. Thenumber of a frame or half-frame to which the detected SSB belongs to maybe identified by SFN information and half-frame indication information.

Specifically, the UE may obtain 10-bit SFN system information s0 to s9from the PBCH. 6 bits out of the 10-bit SFN information is obtained froma master information block (MIB), and the remaining 4 bits are obtainedfrom a PBCH transport block (TB).

The UE may then obtain 1-bit half-frame indication information c0. Whena carrier frequency is 3 GHz or below, the half-frame indicationinformation may be signaled implicitly by a PBCH DMRS. The PBCH DMRSuses one of 8 PBCH DMRS sequences to indicate 3-bit information.Therefore, when L=4, the remaining one bit except for bits indicating anSSB index among 3 bits that may be indicated by the 8 PBCH DMRSsequences may be used as a half-frame indication.

Finally, the UE may obtain an SSB index based on the DMRS sequence andPBCH payload. SSB candidates are indexed with 0 to L−1 in time order inan SSB burst set (i.e., half-frame). When L=8 or L=64, three leastsignificant bits (LSBs) b0, b1 and b2 of an SSB index may be indicatedby 8 different PBCH DMRS sequences. When L=64, three most significantbits (MSBs) b3, b4 and b5 of the SSB index are indicated by the PBCH.When L=2, two LSBs b0 and b1 of the SSB index may be indicated by 4different PBCH DMRS sequences. When L=4, the remaining one bit b2 exceptfor the bits indicating the SSB index among the three bits may be usedas a half-frame indication.

System Information Acquisition

FIG. 8 illustrates a system information (SI) acquisition procedure whichvarious embodiments of the present disclosure are applicable.

The UE may obtain access stratum (AS)-/non-access stratum(NAS)-information in the SI acquisition procedure. The SI acquisitionprocedure may be applied to UEs in RRC_IDLE, RRC_INACTIVE, andRRC_CONNECTED states.

The SI may be divided into a Master Information Block (MIB) and aplurality of System Information Blocks (SIBs). The SI other than the MIBmay be referred to as Remaining Minimum System Information (RMSI), whichwill be described below in detail.

-   -   The MIB may include information/parameters related to reception        of SystemInformationBlockType1 (SIB1) and may be transmitted        through the PBCH of the SSB.    -   The MIB may include information/parameters related to reception        of SystemInformationBlockType1 (SIB1) and may be transmitted        through the PBCH of the SSB. Information of the MIB may be        understood with reference to 3GPP TS 38.331 and may include the        following fields.    -   subCarrierSpacingCommon ENUMERATED {scs15or60, scs30or120},    -   ssb-SubcarrierOffset INTEGER (0 . . . 15),    -   pdcch-ConfigSIB1 INTEGER (0 . . . 255),    -   dmrs-TypeA-Position ENUMERATED {pos2, pos3},    -   . . .    -   spare BIT STRING (SIZE (1))

Descriptions of the fields are shown in Table 9 below.

TABLE 9 pdcch-ConfigSIB1 Determines a common ControlResourceSet(CORESET), a common search space and necessary PDCCH parameters. If thefield ssb-SubcarrierOffset indicates that SIB1 is absent, the fieldpdcch-ConfigSIB1 indicates the frequency positions where the UE may findSS/PBCH block with SIB1 or the frequency range where the network doesnot provide SS/PBCH block with SIB1 (see TS 38.213, clause 13).ssb-SubcarrierOffset Corresponds to k_(SSB) (see TS 38.213), which isthe frequency domain offset between SSB and the overall resource blockgrid in number of subcarriers. (See TS 38.211, clause 7.4.3.1). Thevalue range of this field may be extended by an additional mostsignificant bit encoded within PBCH as specified in TS 38.213. Thisfield may indicate that this cell does not provide SIB1 and that thereis hence no CORESET#0 configured in MIB (see TS 38.213, clause 13). Inthis case, the field pdcch-ConfigSIB1 may indicate the frequencypositions where the UE may (not) find a SS/PBCH with a control resourceset and search space for SIB1 (see TS 38.213, clause 13).subCarrierSpacingCommon Subcarrier spacing for SIB1, Msg.2/4 for initialaccess, paging and broadcast SI-messages. If the UE acquires this MIB onan FRI carrier frequency, the value scs15or60 corresponds to 15 kHz andthe value scs30or120 corresponds to 30 kHz. If the UE acquires this MIBon an FR2 carrier frequency, the value scs15or60 corresponds to 60 kHzand the value scs30or120 corresponds to 120 kHz. dmrs-TypeA-PositionPosition of (first) DM-RS for downlink (e.g., PDSCH) and uplink (e.g.,PUSCH), pos2 represents the 2^(nd) symbol in a slot and pos2 representsthe 3rd symbol in a slot.

When selecting an initial cell, the UE may assume that a half-framehaving the SSB is repeated at a period of 20 ms. The UE may checkwhether a Control Resource Set (CORESET) (e.g., CORESET #0) for aType0-PDCCH common search space is present based on the MIB. Ink_(SSB)<=23 (for FR1) or k_(SSB)<=11 (for FR2), the UE may determinethat the CORESET for the Type0-PDCCH common search space is present. Inthe case of k_(SSB)>23 (for FR1) or k_(SSB)>11 (for FR2), the UE maydetermine that the CORESET for the Type0-PDCCH common search space isnot present. The Type0-PDCCH common search space may be a type of aPDCCH search space and may be used to transmit a PDCCH for scheduling anSI message. When the Type0-PDCCH common search space is present, the UEmay determine (i) a plurality of consecutive RBs included in the CORESET(e.g., CORESET #0) and one or more consecutive symbols and (ii) a PDCCHoccasion (i.e., a location in the time domain for reception of thePDCCH) (e.g., search space #0) based on information in the MIB (e.g.,pdcch-ConfigSIB1). When the Type0-PDCCH common search space is notpresent, the pdcch-ConfigSIB1 may provide information on a frequencyposition at which SSB/SIB1 is present and a frequency range in which theSSB/SIB1 is not present.

The SIB1 may include information related to the availability andscheduling (e.g., a transmission period and an SI-window size) of theremaining SIBs (hereinafter an SIBx, x being an integer equal to orgreater than 2). For example, the SIB1 may inform whether SIBx isperiodically broadcast or is provided in response to a request of the UEusing an on-demand method. When the SIBx is provided using the on-demandmethod, the SIB1 may include information required to make a request forthe SI by the UE. The SIB1 may be transmitted through a PDSCH, a PDCCHfor scheduling the SIB1 may be transmitted through the Type0-PDCCHcommon search space, and the SIB1 may be transmitted through a PDSCHindicated by the PDCCH.

The SIBx may be included in an SI message and may be transmitted througha PDSCH. Each SI message may be transmitted within a window (i.e., anSI-window) that is periodically generated.

Beam Alignment

FIG. 9 is a diagram illustrating exemplary multi-beam transmission towhich various embodiments are applicable.

Beam sweeping refers to changing the beam (direction) of a radio signalover time by a transmission reception point (TRP) (e.g., BS/cell)(hereinafter, the terms beam and beam direction are interchangeablyused). SSBs may be transmitted periodically by beam sweeping. In thiscase, SSB indices are implicitly linked to SSB beams. An SSB beam may bechanged on an SSB (index) basis or on an SS (index) group basis. In thelatter, the same SSB beam is maintained in an SSB (index) group. Thatis, the transmission beam direction of an SSB is repeated for aplurality of contiguous SSBs. The maximum number of times that the SSBis transmitted in an SSB burst set, L may have a value of 4, 8, or 64depending on the frequency band of a carrier. Accordingly, the maximumnumber of SSB beams in the SSB burst set may be given according to thefrequency band of the carrier as follows.

-   -   For frequency range up to 3 GHz, Max number of beams=4    -   For frequency range from 3 GHz to 6 GHz, Max number of beams=8    -   For frequency range from 6 GHz to 52.6 GHz, Max number of        beams=64

When multi-beam transmission is not applied, the number of SSB beams is1.

When the UE attempts to initially access the BS, the UE may align beamswith those of the BS based on the SSB. For example, the UE identifiesthe best SSB after performing SSB detection. Thereafter, the UE maytransmit a RACH preamble to the BS on a PRACH resourcelinked/corresponding to the index (i.e., beam) of the best SSB. The SSBmay be used to align beams between the BS and UE after the initialaccess.

Channel Measurement and Rate-Matching

FIG. 10 is a diagram illustrating a method of indicating an actuallytransmitted SSB (SSB_tx) to which various embodiments are applicable.

A maximum of L SSBs may be transmitted in an SSB burst set, and thenumber and positions of actually transmitted SSBs may vary for eachBS/cell. The number and positions of actually transmitted SSBs may beused for rate-matching and measurement, and information about actuallytransmitted SSBs (e.g., ssb-PositionsInBurst) may be indicated asfollows.

-   -   When the number and positions of actually transmitted SSBs are        related to rate-matching, the information may be indicated by        UE-specific RRC signaling or RMSI. The UE-specific RRC signaling        includes a full bitmap (e.g., of length L) for frequency ranges        below and above 6 GHz. The RMSI includes a full bitmap for        frequency ranges below 6 GHz and a compressed bitmap for        frequency ranges above 6 GHz. Specifically, the information        about actually transmitted SSBs may be indicated by group-bitmap        (8 bits)+intra-group bitmap (8 bits). Resources (e.g., REs)        indicated by the UE-specific RRC signaling or RMSI may be        reserved for SSB transmission, and a PDSCH and/or PUSCH may be        rate-matched in consideration of the SSB resources.    -   When the number and positions of actually transmitted SSBs are        related to measurement, the network (e.g., BS) may indicate an        SSB set to be measured within a measurement period if the UE is        in the RRC connected mode. The SSB set may be indicated for each        frequency layer. If no SSB set is indicated, a default SSB set        may be used. The default SSB set includes all SSBs within the        measurement period. The SSB set may be indicated by a full        bitmap (e.g., of length L) of RRC signaling. When the UE is in        the RRC idle mode, the default SSB set is used.

2. Random Access (RACH) Procedure

When a UE initially accesses a BS or has no radio resources for a signaltransmission, the UE may perform a random access procedure with the BS.

The random access procedure is used for various purposes. For example,the random access procedure may be used for initial network access in anRRC_IDLE state, an RRC connection reestablishment procedure, handover,UE-triggered UL data transmission, transition in an RRC_INACTIVE state,time alignment establishment in SCell addition, OSI request, and beamfailure recovery. The UE may acquire UL synchronization and ULtransmission resources in the random access procedure.

Random access procedures may be classified into a contention-basedrandom access procedure and a contention-free random access procedure.The contention-based random access procedure is further branched into a4-step random access (4-step RACH) procedure and a 2-step random access(2-step RACH) procedure.

2.1. 4-Step RACH: Type-1 Random Access Procedure

FIG. 14 is a diagram illustrating an exemplary 4-step RACH procedure towhich various embodiments of the present disclosure are applicable.

When the (contention-based) random access procedure is performed in foursteps (4-step RACH procedure), the UE may transmit a message (Message 1(Msg1)) including a preamble related to a specific sequence on a PRACH(1401) and receive a PDCCH and a response message (RAR message) (Message2 (Msg2)) for the preamble on a PDSCH corresponding to the PDCCH (1403).The UE transmits a message (Message 3 (Msg3)) including a PUSCH based onscheduling information included in the RAR (1405) and perform acontention resolution procedure involving reception of a PDCCH signaland a PDSCH signal corresponding to the PDCCH signal. The UE may receivea message (Message 4 (Msg4)) including contention resolution informationfor the contention resolution procedure from the BS (1707).

The 4-step RACH procedure of the UE may be summarized in Table 10 below.

TABLE 10 Type of Signals Operations/Information obtained 1^(st) stepPRACH preamble in UL Initial beam obtainment Random selection ofRA-preamble ID 2^(nd) step Random Access Timing Advanced informationResponse on DL-SCH RA-preamble ID Initial UL grant, Temporary C-RNTI3^(rd) step UL transmission on RRC connection request UL-SCH UEidentifier 4^(th) step Contention Resolution Temporary C-RNTI on PDCCHfor on DL initial access C-RNTI on PDCCH for UE in RRC_CONNECTED

In the random access procedure, the UE may first transmit an RACHpreamble as Msg1 on a PRACH.

Random access preamble sequences of two different lengths are supported.The longer sequence length 839 is applied to the SCSs of 1.25 kHz and 5kHz, whereas the shorter sequence length 139 is applied to the SCSs of15 kHz, 30 kHz, 60 kHz, and 120 kHz.

Multiple preamble formats are defined by one or more RACH OFDM symbolsand different CPs (and/or guard times). An RACH configuration for a cellis provided in system information of the cell to the UE. The RACHconfiguration includes information about a PRACH SCS, availablepreambles, and a preamble format. The RACH configuration includesinformation about associations between SSBs and RACH (time-frequency)resources. The UE transmits a RACH preamble in RACH time-frequencyresources associated with a detected or selected SSB.

An SSB threshold for RACH resource association may be configured by thenetwork, and an RACH preamble is transmitted or retransmitted based onan SSB having a reference signal received power (RSRP) measurementsatisfying the threshold. For example, the UE may select one of SSBssatisfying the threshold, and transmit or retransmit the RACH preamblein an RACH resource associated with the selected SSB. For example, whenretransmitting the RACH preamble, the UE may reselect one of the SSBsand retransmit the RACH preamble in an RACH resource associated with thereselected SSB. That is, the RACH resource for the retransmission of theRACH preamble may be identical to and/or different from the RACHresource for the transmission of the RACH preamble.

Upon receipt of the RACH preamble from the UE, the BS transmits an RARmessage (Msg2) to the UE. A PDCCH that schedules a PDSCH carrying theRAR is cyclic redundancy check (CRC)-masked by a random access radionetwork temporary identifier (RA-RNTI) and transmitted. Upon detectionof the PDCCH masked by the RA-RNTI, the UE may receive the RAR on thePDSCH scheduled by DCI carried on the PDCCH. The UE determines whetherthe RAR includes RAR information for its transmitted preamble, that is,Msg1. The UE may make the determination by checking the presence orabsence of the RACH preamble ID of its transmitted preamble in the RAR.In the absence of the response to Msg1, the UE may retransmit the RACHpreamble a predetermined number of or fewer times, while performingpower ramping. The UE calculates PRACH transmission power for thepreamble retransmission based on the latest pathloss and a power rampingcounter.

The RAR information may include a preamble sequence transmitted by theUE, a temporary cell RNTI (TC-RNTI) that the BS has allocated to the UEattempting random access, UL transmit time alignment information, ULtransmission power adjustment information, and UL radio resourceallocation information. Upon receipt of its RAR information on a PDSCH,the UE may acquire time advance information for UL synchronization, aninitial UL grant, and a TC-RNTI. The timing advance information is usedto control a UL signal transmission timing. For better alignment betweena PUSCH/PUCCH transmission of the UE and a subframe timing of a networkend, the network (e.g., the BS) may measure the time difference betweena PUSCH/PUCCH/SRS reception and a subframe and transmit the timingadvance information based on the time difference. The UE may transmit aUL signal as Msg3 of the random access procedure on a UL-SCH based onthe RAR information. Msg3 may include an RRC connection request and a UEID. The network may transmit Msg4 in response to Msg3. Msg4 may betreated as a contention resolution message on DL. As the UE receivesMsg4, the UE may enter an RRC_CONNECTED state.

As described before, the UL grant included in the RAR schedules a PUSCHtransmission to the BS. A PUSCH carrying an initial UL transmissionbased on the UL grant of the RAR is referred to as an Msg3 PUSCH. Thecontent of the RAR UL grant starts from the most significant bit (MSB)and ends in the least significant bit (LSB), given as Table 11.

TABLE 11 RAR UL grant field Number of bits Frequency hopping flag 1 Msg3PUSCH frequency resource allocation 12 Msg3 PUSCH time resourceallocation 4 Modulation and coding scheme (MCS) 4 Transmit power control(TPC) for Msg3 PUSCH 3 CSI request 1

A transmit power control (TPC) command is used to determine thetransmission power of the Msg3 PUSCH. For example, the TPC command isinterpreted according to Table 12.

TABLE 12 TPC command value [dB] 0 −6   1 −4   2 −2   3 0 4 2 5 4 6 6 7 8

2.2. 2-Step RACH: Type-2 Random Access Procedure

FIG. 12 is a diagram illustrating an exemplary 2-step RACH procedure towhich various embodiments of the present disclosure are applicable.

The (contention-based) RACH procedure performed in two steps, that is,the 2-step RACH procedure has been proposed to simplify the RACHprocedure and thus achieve low signaling overhead and low latency.

In the 2-step RACH procedure, the operation of transmitting Msg1 and theoperation of transmitting Msg3 in the 4-step RACH procedure may beincorporated into an operation of transmitting one message, Message A(MsgA) including a PRACH and a PUSCH by the UE. The operation oftransmitting Msg2 by the BS and the operation of transmitting Msg4 bythe BS in the 4-step RACH procedure may be incorporated into anoperation of transmitting one message, Message B (MsgB) including an RARand contention resolution information.

That is, in the 2-step RACH procedure, the UE may combine Msg1 and Msg3of the 4-step RACH procedure into one message (e.g., MsgA) and transmitthe message to the BS (1201).

Further, in the 2-step RACH procedure, the BS may combine Msg2 and Msg4of the 4-step RACH procedure into one message (e.g., MsgB) and transmitthe message to the UE (1203).

The 2-step RACH procedure may become a low-latency RACH procedure basedon the combinations of these messages.

More specifically, MsgA may carry a PRACH preamble included in Msg1 anddata included in Msg3 in the 2-step RACH procedure. In the 2-step RACHprocedure, MsgB may carry an RAR included in Msg2 and contentionresolution information included in Msg4.

2.3. Contention-Free RACH

FIG. 13 is a diagram illustrating an exemplary contention-free RACHprocedure to which various embodiments of the present disclosure areapplicable.

The contention-free RACH procedure may be used for handover of the UE toanother cell or BS or may be performed when requested by a BS command.The contention-free RACH procedure is basically similar to thecontention-based RACH procedure. However, compared to thecontention-based RACH procedure in which a preamble to be used israndomly selected from among a plurality of RACH preambles, a preambleto be used by the UE (referred to as a dedicated RACH preamble) isassigned to the UE by the BS in the contention-free RACH procedure(1901). Information about the dedicated RACH preamble may be included inan RRC message (e.g., a handover command) or provided to the UE by aPDCCH order. When the RACH procedure starts, the UE transmits thededicated RACH preamble to the BS (1903). When the UE receives an RARfrom the BS, the RACH procedure is completed (1905).

In the contention-free RACH procedure, a CSI request field in an RAR ULgrant indicates whether the UE is to include an aperiodic CSI report ina corresponding PUSCH transmission. An SCS for the Msg3 PUSCHtransmission is provided by an RRC parameter. The UE may transmit thePRACH and the Msg3 PUSCH in the same UL carrier of the same servingcell. A UL BWP for the Msg3 PUSCH transmission is indicated by SIB1.

2.4. Mapping Between SSB Block and PRACH Resource (Occasion)

FIGS. 14 and 15 are diagrams showing an example of transmission of an SSblock and a PRACH resource linked to the SS block according to variousembodiments of the present disclosure.

In order for a BS to communicate with one UE, an optimum beam directionbetween the BS and the UE needs to be found, and as the UE moves, theoptimum beam direction may be changed, and thus the optimum beamdirection needs to be continuously tracked. A procedure of finding theoptimum beam direction between a BS and a UE may be referred to as abeam acquisition procedure, and a procedure of continuously tracking theoptimum beam direction may be referred to as a beam tracking procedure.The procedure may be required for a state in which the optimum beam islost and communication with the BS is not capable of being maintained inan optimum communication state or enters a state in which communicationis impossible, that is, beam recovery for recovering beam failureduring 1) initial access in which the UE attempts first access to theBS, 2) handover from one BS to another BS, and 3) beam tracking offinding an optimum beam between the UE and the BS.

A multi-step beam acquisition procedure is being discussed for beamacquisition in an environment using multiple beams in the case of the NRsystem. In the multi-step beam acquisition procedure, the BS and the UEmay perform connection setup using a wide beam in an initial accessstage, and after the connection setup is completed, the BS and the UEmay perform communication with the optimum quality using a narrow beam.An example of the beam acquisition procedure in an NR system to whichvarious embodiments of the present disclosure will be described below.

1) The BS may transmit a synchronization block for each wide bam inorder for the UE to find a BS in an initial access stage, that is, toperform cell search or cell acquisition, to measure the quality for achannel for each beam of a wide beam, and to find an optimum wide beamto be used in a primary stage of beam acquisition.

2) The UE may perform cell search on a synchronization block for eachbeam and may perform DL beam acquisition using a detection result foreach beam.

3) The UE may perform an RACH procedure in order to inform that the UEintends to access a BS that the UE finds.

4) In order for the UE to notify the BS of the DL beam acquisitionresult (e.g., a beam index) at a wide beam level simultaneously with theRACH procedure, the BS may connect or relate a synchronization blocktransmitted for each beam and a PRACH resource to be used for PRACHtransmission. When the UE performs the RACH procedure using the PRACHresource connected to the optimum beam direction that the UE finds, theBS may acquire information on a DL beam appropriate for the UE during aprocedure of receiving a PRACH preamble.

In a multi-beam environment, it may be important to accurately determinea Tx beam and/or a Rx beam direction between the UE and a transmissionand reception point (TRP) by the UE and/or the TRP. In the multi-beamenvironment, beam sweeping for repeatedly transmitting a signal orreceiving a signal depending on TX/RX reciprocal capability of the TRP(e.g., a BS) or a UE may be considered. The TX/RX reciprocal capabilitymay be referred to as TX/RX beam correspondence in the TRP and the UE.In the multi-beam environment, when the TX/RX reciprocal capability inthe TRP and the UE is not held, the UE may shoot a UL signal in a beamdirection in which the UE receives a DL signal. This is because anoptimum path of UL and an optimum path of DL are different. The TX/RXbeam correspondence in the TRP may be held when the TRP determines a TRPRX beam for corresponding UL reception based on DL measurement of the UEwith respect to one or more TX beams of the TRP and/or the TRPdetermines a TRP TX beam for corresponding DL transmission based on ULmeasurement of TRP′ with respect to one or more RX beams of the TRP. TheTX/RX beam correspondence in the UE may be held when the UE determines aUE RX beam for corresponding UL transmission based on DL measurement ofthe UE with respect to one or more RX beams of the UE and/or the UEdetermines a UE RX beam for corresponding DL reception based onindication of the TRP based on UL measurement with respect to one ormore TX beams of the UE.

2.5. PRACH Preamble Structure

In an NR system, an RACH signal used for initial access to a BS, thatis, initial access to the BS through a cell used by the BS may beconfigured using the following factors.

-   -   Cyclic prefix (CP): This may prevent interface from a        previous/forward (OFDM) symbol and may bundle PRACH preamble        signals reaching a BS with various time delays in the same time        zone. That is, when the CP is set to be appropriate for the        maximum cell radius, PRACH preambles transmitted in the same        resource by UEs in the cell may enter a PRACH reception window        corresponding to the length of a PRACH preamble set by the BS        for PRACH reception. The length of the CP may be generally set        to be equal to or greater than the maximum round trip delay. The        CP may have a length TCP.    -   Preamble (sequence): A sequence for detecting transmission of a        signal by a BS may be defined, and a preamble may carry the        sequence. The preamble sequence may have a length TSEQ.    -   Guard time (GT): This may be a duration defined to prevent a        PRACH signal that is transmitted from the farthest to the BS in        PRACH coverage and arrives at the BS with delay from interfering        with a signal arriving at the BS after a PRACH symbol duration,        and the UE does not transmit a signal during the duration, and        thus the GT may not be defined based on the PRACH signal. The GT        may have a length TGP.

2.6. Mapping to Physical Resources for Physical Random-Access Channel

A random-access preamble may be transmitted within only a time resourceacquired based on a RACH configuration table that is preconfigured forRACH configuration, FR1, FR2, and a preconfigured spectrum type.

A PRACH configuration index in the RACH configuration table may be givenas follows.

-   -   For a RACH configuration table for Random access configurations        for FR1 and an unpaired spectrum, the PRACH configuration index        in the RACH configuration table may be given from a higher layer        parameter prach-ConfigurationIndexNew (if configured).        Otherwise, the PRACH configuration index in the RACH        configuration table may be given from prach-ConfigurationIndex,        msgA-prach-ConfigurationIndex, msgA-prach-ConfigurationIndexNew        (if configured), or the like.    -   The PRACH configuration index in the RACH configuration table        may be given from higher layer parameter        prach-ConfigurationIndex, msgA-prach-ConfigurationIndexNew (if        configured), or the like for a RACH configuration table about        Random access configurations for FR1 and paired        spectrum/supplementary uplink and a RACH configuration table        about Random access configurations for FR2 and unpaired        spectrum.

The RACH configuration table may be a table about a relationship betweenone or more of a PRACH configuration Index, a Preamble format, n_(SFN)mod x=y, a Subframe number, a Starting symbol, the Number of PRACHslots, the number of time-domain PRACH occasions within a PRACH slot,and a PRACH duration in cases.

The cases will be described below:

-   -   (1) Random access configurations for FR1 and paired        spectrum/supplementary uplink    -   (2) Random access configurations for FR1 and unpaired spectrum    -   (3) Random access configurations for FR2 and unpaired spectrum

Table 13 below shows a portion of an example of a RACH configurationindex for (2) Random access configurations for FR1 and unpairedspectrum.

TABLE 13 N_(t) ^(RA,slot), number of time- Number domain of PRACH PRACHoccasions PRACH slots within a N_(dur) ^(RA), Configuration Preamblen_(f) mod x = y Subframe Starting within a PRACH PRACH Index format x ynumber symbol subframe slot duration 0 0 16  1 9 0 — — 0 1 0 8 1 9 0 — —0 2 0 4 1 9 0 — — 0 3 0 2 0 9 0 — — 0 4 0 2 1 9 0 — — 0 5 0 2 0 4 0 — —0 6 0 2 1 4 0 — — 0 7 0 1 0 9 0 — — 0 8 0 1 0 8 0 — — 0 9 0 1 0 7 0 — —0 . . .

The RACH configuration table shows specific values for parameters (e.g.,preamble format, periodicity, SFN offset, RACH subframe/slot index,starting OFDM symbol, number of RACH slots, number of occasions, OFDMsymbols for RACH format, etc.) required to configure RACH occasions.When the RACH configuration index is indicated, specific values relatedto the indicated index may be used.

For example, when the starting OFDM symbol parameter is n, one or moreconsecutive (time-domain) RACH occasions may be configured from an OFDMsymbol having index #n.

For example, the number of one or more RACH occasions may be indicatedby the following parameter: number of time-domain PRACH occasions withina RACH slot.

For example, a RACH slot may include one or more RACH occasions.

For example, the number of RACH slots (in a subframe and/or slot with aspecific SCS) may be indicated by the parameter: number of RACH slots.

For example, a system frame number (SFN) including RACH occasions may bedetermined by n_(SFN) mod x=y, where mod is a modular operation (moduloarithmetic or modulo operation) which is an operation to obtainremainder r obtained by dividing dividend q by divisor d (r=q mod(d)).

For example, a subframe/slot (index) including RACH occasions in asystem frame may be indicated by the parameter: RACH subframe/slotindex.

For example, a preamble format for RACH transmission/reception may beindicated by the parameter: preamble format.

Referring to FIG. 16(a), for example, when the starting OFDM symbol isindicated as 0, one or more consecutive (time-domain) RACH occasions maybe configured from OFDM symbol #0. For example, the number of one ormore RACH occasions may depend on a value indicated by the parameter:number of time-domain RACH occasions within a RACH slot. For example,the preamble format may be indicated by the parameter: preamble format.For example, preamble formats A1, A2, A3, B4, C0, C2, etc. may beindicated. For example, one of the last two OFDM symbols may be used asthe GT, and the other may be used for transmission of other UL signalssuch as a PUCCH, a sounding reference signal (SRS), etc.

Referring to FIG. 16(b), for example, when the starting OFDM symbol isindicated by 2, one or more consecutive (time-domain) RACH occasions maybe configured from OFDM symbol #2. For example, 12 OFDM symbols may beused for a RACH occasion, and no GT may be configured in the last OFDMsymbol. For example, the number of one or more RACH occasions may dependon a value indicated by the parameter: number of time-domain RACHoccasions within a RACH slot. For example, the preamble format may beindicated by the parameter: preamble format. For example, preambleformats A1/B1, B1, A2/B2, A3/B3, B4, C0, C2, etc. may be indicated.

Referring to FIG. 16(c), for example, when the starting OFDM symbol isindicated as 7, one or more consecutive (time-domain) RACH occasions maybe configured from OFDM symbol #7. For example, 6 OFDM symbols may beused for an RACH occasion, and the last OFDM symbol (OFDM symbol #13)may be used for transmission of other UL signals such as a PUCCH, anSRS, etc. For example, the number of one or more RACH occasions maydepend on a value indicated by the parameter: number of time-domain RACHoccasions within a RACH slot. For example, the preamble format may beindicated by the parameter: preamble format. For example, preambleformats A1, B1, A2, A3, B3, B4, C0, C2, etc. may be indicated.

For example, the parameters included in the RACH configuration table maysatisfy predetermined correspondence relationships identified/determinedby the RACH configuration table and the RACH configuration index. Forexample, the predetermined correspondence relationships may be satisfiedbetween the following parameters: PRACH configuration index, RACHformat, period (x)=8, SFN offset (y), subframe number, starting symbol(index), number of PRACH slots within a subframe, number of PRACHoccasions within a PRACH slot, PRACH duration/OFDM symbols for RACHformat, etc. The correspondence relationships may be identified by theRACH configuration index and the RACH configuration table.

3. Various Embodiments of the Present Disclosure

A detailed description will be given of various embodiments of thepresent disclosure based on the above technical ideas. Theafore-described contents of clause 1 and clause 2 are applicable tovarious embodiments of the present disclosure described below. Forexample, operations, functions, terminologies, and so on which are notdefined in various embodiments of the present disclosure may beperformed and described based on clause 1 and clause 2.

Symbols/abbreviations/terms used in the description of variousembodiments of the present disclosure may be defined as follows.

-   -   A/B/C: A and/or B and/or C    -   BWP: bandwidth part    -   CBRA: contention-based random access    -   CDM: code division multiplexing (code domain sharing)    -   Comb: a comb may refer to a method of mapping signals at regular        intervals in the frequency domain. For example, comb 2 (comb-2        or 2-comb) may mean mapping the same specific RS to each RE        spaced by two subcarriers. Comb 4 (comb-4 or 4-comb) may mean        mapping the same specific RS to each RE spaced by four        subcarriers.    -   CFRA: contention-free random access    -   CP-OFDM: cyclic prefix based orthogonal frequency division        multiplex, which may be understood as a case in which transform        precoding is disabled.    -   DFT-s-OFDM: discrete Fourier transform spread orthogonal        frequency division multiplex, which may be understood as a case        in which transform precoding is enabled.    -   DL: downlink    -   DM-RS (DMRS): demodulation reference signal    -   FDM: frequency division multiplexing (frequency domain sharing)    -   MCS: modulation and coding scheme    -   OCC: orthogonal cover code    -   OFDM: orthogonal frequency division multiplexing    -   PAPR: peak to average power ratio    -   PRACH: physical random access channel    -   PRB: physical resource block    -   PRU: PUSCH resource unit    -   PO: PUSCH occasion    -   PUSCH: physical uplink shared channel    -   RA: random access    -   RACH: random access channel    -   RAPID: random access preamble identifier    -   RAR: random access response    -   RB: resource block    -   RE: resource element    -   RNTI: radio network temporary identifier    -   RO: RACH occasion or PRACH occasion    -   SCID: scrambling identifier    -   TBS: transmission block size    -   TDM: time division multiplexing (time domain sharing)    -   UL: uplink    -   Rel-15 (REL. 15): Rel-15 refers to 3GPP technical specification        (TS) Release 15. Additionally/alternatively, Rel-15 means a        system supporting 3GPP TS Release 15 and/or a system capable of        coexistence therewith.    -   Rel-16 (REL. 16): Rel-16 refers 3GPP TS Release 16.        Additionally/alternatively, Rel-15 means a system supporting        3GPP TS Release 16 and/or a system capable of coexistence        therewith.

In the description of various embodiments, when it is said thatsomething is more than/more than or equal to A, it may be interpreted tomean that A is more than or equal to/more than A.

In the description of various embodiments, when it is said thatsomething is less than/less than or equal to B, it may be interpreted tomean that the thing is less than or equal to/less than B.

In the description of various embodiments, unless otherwise specified,(transmission of) a PUSCH may be included in (transmission of) MsgA.

In the description of various embodiments, unless otherwise stated,PUSCH/PO/PRU may be interchanged.

In the 2-step RACH procedure, MsgA transmitted in UL may include a PRACHpreamble and a PUSCH resource. For example, the PRACH preamble and thePUSCH resource may be mapped together based on an SSB, and it may bedifficult to establish such a relationship in a simple way. For example,the state of an RO (e.g., a periodicity, the number of available ROs, anSSB-to-RO mapping relationship, etc.) and a PUSCH configuration (e.g., aperiodicity, the number of available ROs/POs, the number of DMRS antennaports/sequences, etc.) may be considered together.

Various embodiments may relate to a method of configuring a MsgA PUSCH.

Various embodiments may relate to a method of configuring a DMRS for aMsgA PUSCH.

Various embodiments may relate to a RACH preamble-to-PUSCH (resourceunit) mapping method for supporting the 2-step RACH procedure.

FIG. 17 is a diagram schematically illustrating a method of operating aUE and a BS according to various embodiments of the present disclosure.

FIG. 18 is a diagram schematically illustrating a method of operating aUE according to various embodiments.

FIG. 19 is a diagram schematically illustrating a method of operating aBS according to various embodiments.

Referring to FIGS. 17 to 19 , in operations 1701 and 1801 according tovarious embodiments, the UE may obtain/generate MsgA. For example, theUE may obtain/generate MsgA by mapping a PRACH preamble to an RO,mapping a PUSCH to a PO, and/or mapping a DMRS.

In operations 1703, 1803, and 1901 according to various embodiments, theUE may transmit MsgA, and the BS may receive MsgA.

In operations 1705 and 1903 according to various embodiments, the BS maydecode (detect) MsgA. For example, the BS may decode MsgA to obtain aPRACH preamble, a PUSCH, and/or a DMRS included in MsgA.

In operations 1707, 1805, 1905 according to various embodiments, the BSmay transmit MsgB and/or Msg2 in response to MsgA, and the UE mayreceive MsgB and/or Msg2.

Specific operations, functions, terms, etc. according to each exemplaryembodiment may be performed and described based on various embodimentsto be described later.

Hereinafter, various embodiments will be described in detail. It may beclearly understood by those of ordinary skill in the art that thevarious embodiments described below may be combined in whole or in partto constitute other embodiments unless mutually exclusive.

3.1. DMRS for MsgA PUSCH

DMRS Configuration Type for MsgA PUSCH

According to various embodiments, only Type 1 DMRS may be applied to aMsgA PUSCH of the 2-step RACH procedure.

In the NR system to which various embodiments are applicable, two DMRStypes: DMRS configuration type 1 and DMRS configuration type 2 may besupported. For example, the DMRS type may be configured by dmrs-Type. Ifthere is no corresponding information element (IE) (if the informationis absent), DMRS type 1 may be used.

For example, for configuration type 1, the minimum REG may be one RE inthe frequency domain. For example, for configuration type 2, the minimumREG may be two consecutive REs in the frequency domain.

For example, for configuration type 1, three pairs (6 REs) of DMRSs maybe distributed in one OFDM symbol/one RB at an interval of four REs. TwoREs in each pair may be separated by an interval of two REs. Forexample, 6 REs of a DMRS symbol may all be distributed to different REsin the frequency domain. For a double-symbol DMRS, 8 DMRS ports (ports1000 to 1007) may be supported. For a single-symbol DMRS, four DMRSports (ports 1000 to 1003) may be supported.

For example, for configuration type 2, two pairs (4 REs) of DMRSs may bedistributed in one OFDM symbol/one RB at an interval of 6 REs. Two REsin each pair may be separated by an interval of one RE, which may meanthat the two REs of each pair are contiguous. For a dual-symbol DMRS, 12DMRS ports (ports 1000 to 1011) may be supported. For a single-symbolDMRS, 8 DMRS ports (ports 1000 to 1007) may be supported.

According to various embodiments, a Type 1 DMRS may be applied to a Msg3PUSCH of the 4-step RACH procedure. For example, the Type 1 DMRS may beused for Msg3 transmission in a specific UL BWP.

According to various embodiments, considering that a RACH configurationfor the 2-step RACH procedure may be configured by BWP-UplinkCommonapplicable to UEs, only the Type 1 DMRS may be applied to the MsgA PUSCHin the 2-step RACH procedure. For example, BWP-UplinkCommon may be acell-specific IE used to configure a common parameter for a UL BWP.

PUSCH DMRS Port/Sequence

According to various embodiments, the network (e.g., BS) may configurethe number of antenna ports for a MsgA PUSCH DMRS.

According to various embodiments, the maximum number of antenna portsmay be 4.

For example, when the number of configured antenna ports is 2, antennaport 0 and antenna port 1 may be used.

For example, when the number of configured antenna ports is 1, antennaport 0 may be used.

According to various embodiments, for the Type 1 DMRS, when one OFDMsymbol is used, a maximum of four antenna ports may be allocated. Forexample, the antenna ports may be configured with frequency resources(e.g., 2-comb type resources) and cyclic shift values (e.g., 0 and π(pi)).

According to various embodiments, PRACH preamble mapping may be defined.

According to various embodiments, PRACH preambles may be mapped to validPRUs within a MsgA association period in the following order:

-   -   First, in ascending order of frequency resource indices for        frequency-multiplexed POs    -   Second, in ascending order of DMRS indices within a single PO        -   The DMRS indices may be determined in ascending order of            DMRS port indices first and in ascending order of DMRS            sequence indices second.    -   Third, in ascending order of time resource indices for        time-multiplexed POs within one PUSCH slot    -   Fourth, in ascending order of PUSCH slot indices    -   For multiple configurations, mapping may be performed between        PRUs of each MsgA PUSCH configuration and preambles in a related        preamble group.        -   Each MsgA PUSCH configuration may identify a subset of DMRS            port/sequence combinations.

For example, one or more consecutive preamble indices of (valid) PRACHoccasions in a slot:

-   -   First, in ascending order of preamble indices within one PRACH        occasion    -   Second, in ascending order of frequency resource indices for        frequency-multiplexed PRACH occasions    -   Third, in ascending order of time resource indices for        time-multiplexed PRACH occasions within a PRACH slot

May be mapped to a (valid) PO:

-   -   First, in ascending order of frequency resource indices for        frequency-multiplexed POs    -   Second, in ascending order of DMRS indices within a PO, where        the DMRS indices may be determined in ascending order of DMRS        port indices first and in ascending order of DMRS sequence        indices second.    -   Third, in ascending order of time resource indices for        time-multiplexed POs within a PUSCH slot    -   Fourth, in ascending order of PUSCH slot indices.

According to various embodiments, a method of indicating DMRS resourcesincluding DMRS ports and/or DMRS sequences may be provided.

In the 4-step RACH procedure, a single antenna port may be applied forMsg3 transmission. However, in the 2-step RACH procedure, all antennaports may be used to improve PUSCH resource efficiency.

According to various embodiments, the network (e.g., BS) may configurethe number of antenna ports for a MsgA PUSCH DMRS.

According to various embodiments, network coverage and/or geometry maybe considered in determining the number of antenna ports. For example,if the network coverage is relatively wide and/or the geometry is notgood to support multiple UEs in a PO, a relatively low number of antennaports (e.g., 1 or 2) may be allocated. On the contrary, for example, ifthe 2-step RACH procedure is performed in relatively narrow networkcoverage and/or with relatively good geometry, it may be allowed toallocate a relatively large number of antenna ports (e.g., 2 or 4) in aPO.

According to various embodiments, if two antenna ports are configured,antenna ports 0 and 1 (or antenna ports 2 and 3) having the samefrequency resource and different cyclic shift values may be used. Thereason for this is that cyclic shift may identify antenna ports even ifthe OFDM symbol reception timing is quite large (e.g., FFT size/4).

Sequence Initialization for MsgA PUSCH DMRS

According to various embodiments, in the case of CP-OFDM (when a DMRS isbased on CP-OFDM or when transform precoding is disabled), a maximum oftwo different initial values and/or seed values may be configured byhigher layer signals (e.g., SIB1 and/or RACH-ConfigCommon). According tovarious embodiments, a sequence may be designated/indicated depending onan RAPID (in the description of various embodiments, the term ‘dependingon’ may be replaced with the following terms: based on, using, etc.).

Additionally/alternatively, according to various embodiments, whentransform precoding is disabled, Equation 1 below may be used for apseudo-random sequence generator for a MsgA PUSCH. According to variousembodiments, when transform precoding is disabled, the pseudo-randomsequence generator for the MsgA PUSCH may be initialized according toEquation 1 below.c _(init)=(2¹⁷(N ^(slot) _(symb) n ^(u) _(s,f)+1+1)(2N ^(nSCID)_(ID)+1)+2N ^(uSCID) _(ID) +n _(SCID))mod 2³¹  [Equation 1]

For example, C_(init) may denote the initial value of the scramblingsequence generator.

For example, N^(slot) _(symb) may denote the number of symbols per slot.

For example, n^(u) _(s,f) may denote a slot number in a frame for SCSconfiguration u.

For example, N⁰ _(ID), N¹ _(ID), . . . , N^(M-1) _(ID)∈{0, 1, . . . ,65535} may be given by higher layer parameters: scramblingID0,scrambling ID1, and scrambling IDM−1 in higher layer signals,respectively.

For example, n_(SCID)∈{0, 1, . . . , M−1} may be designated depending onthe RAPID.

For example, M may have a maximum value of 2.

According to various embodiments, in the case of DFT-s-OFDM (when a DMRSis based on DFT-s-OFDM or when transform precoding is enabled), one rootindex of a Zadoff-Chu (ZC) sequence may be configured by a higher layersignal.

According to various embodiments, multiple DMRS sequences may be appliedper antenna port for enhancement of PUSCH resource efficiency. In thecase of CP-OFDM, a pseudo-noise (PN) sequence may be applied as a DMRSsequence. For UL multi-user multi-input and multi-output (MU-MIMO), twodifferent seed values may be configured by an RRC signal, and one of thetwo seed values may be designated/indicated by DCI. For spatiallyseparated UEs, two different DMRS sequences may be applied even if theUEs are assigned the same antenna port. For a MsgA PUSCH, multiple DMRSsequences may be applied when CP-OFDM is used. The seed values may beconfigured by SIB1 and/or RACH-ConfigCommon, and, the values may bedesignated/indicated depending on the RAPID. Specifically, the seedvalues may be configured by SIB1 and/or RACH-ConfigCommon, and thevalues may be designated/indicated based on the RAPID of at least one ofthe configured seed values. For example, RACH-ConfigCommon may be an IEused to specify a cell-specific random access parameter.

According to various embodiments, for a MsgA PUSCH DMRS, Equation 1described above may be used to initialize a pseudo-random sequencegenerator.

According to various embodiments, for a MsgA PUSCH, the seed values ofEquation 1 (e.g., N⁰ _(ID) and N¹ _(ID)) may be configured by SIB1and/or RACH-ConfigCommon.

According to various embodiments, n_(SCID) of Equation 1 above may bedesignated depending on the RAPID. For example, if a PRU is configuredwith a DMRS port and a DMRS sequence index (e.g., n_(SCID)), n_(SCID)may be automatically obtained from RAPID-to-PRU mapping.

According to various embodiments, in the case of DFT-s-OFDM, a low-PAPRsequence (e.g., ZC sequence) may be applied, and one sequence may beallocated as a DMRS sequence.

According to various embodiments, the number of PRUs in a PO may be oneof {1, 2, 4, 8}.

According to various embodiments, when the number of PRUs in a PO is 1,only one set may be defined for (the number of) DMRS ports and (thenumber of) DMRS sequences.

According to various embodiments, when the number of PRUs in a PO is 2,two sets of combination of a DMRS port and a DMRS sequence (e.g., {2, 1}and {1, 2}) may be defined. For example, when two antenna ports are usedin a PO, one CDM group of two (CDM) groups may be configured for the twoantenna ports.

According to various embodiments, when the number of PRUs in a PO is 4,two sets of combination of a DMRS port and a DMRS sequence (e.g., {4,1}, {2, 2}) may be defined. For example, when four antenna ports areused in a PO, two CDM groups may be used with the same DMRS sequence.For example, when two antenna ports are used in a PO, one CDM group oftwo (CDM) groups may be configured with two different DMRS sequences.

According to various embodiments, when the number of PRUs in a PO is 8,four antenna ports in two CDM groups may be used with two different DMRSsequences. According to various embodiments, if there is no separateconfigurations, two (CDM) groups may be used.

According to various embodiments, multiple PRUs may be defined dependingon a combination of (the number of) DMRS ports and (the number of) DMRSsequences within PO(s).

For example, a set of PRUs in a PO may be defined as shown in Table 14.

TABLE 14 {Number of DMRS ports, Number of PRUs in a PO Number of DMRSsequences 1 {1,1} 2 (2,1}, {1,2} 4 {4,1}, {2,2} 8 {4,2}

For example, when the number of PRUs in a PO is 1, only one set may bedefined for (the number of) DMRS ports and (the number of) DMRSsequences.

For example, when the number of PRUs in a PO is 2, two sets ofcombination of a DMRS port and a DMRS sequence (e.g., {2, 1}, {1, 2})may be defined. For example, when two antenna ports are used in a PO,one CDM group of two (CDM) groups may be configured for the two antennaports.

For example, when the number of PRUs in a PO is 4, two sets ofcombination of a DMRS port and a DMRS sequence (e.g., {4, 1}, {2, 2})may be defined. For example, when four antenna ports are used in a PO,two CDM groups may be used with the same DMRS sequence. For example,when two antenna ports are used in a PO, one CDM group of two (CDM)groups may be configured with two different DMRS sequences.

For example, when the number of PRUs in a PO is 8, four antenna ports intwo CDM groups may be used with two different DMRS sequences. Accordingto various embodiments, if there is no separate configurations, two(CDM) groups may be used.

3.2. MsgA PUSCH Configuration

Msg A PUSCH Scrambling Sequence

According to various embodiments, for a MsgA PUSCH data scramblingsequence, an RA-RNTI and/or an RAPID may be used as the seed value ofsequence initialization for CBRA.

According to various embodiments, for the MsgA PUSCH data scramblingsequence, a C-RNTI may be used as the seed value of sequenceinitialization for CFRA.

According to various embodiments, a value for scrambling sequenceinitialization c_(int) may be configured with n_(RNTI) and n_(ID).

According to various embodiments, it may be determined which values needto be applied to n_(RNTI) and n_(ID) for a MsgA PUSCH of the 2-step RACHprocedure.

For example, in the 4-step RACH procedure, a TC-RNTI/C-RNTI may beapplied as n_(RNTI) for a Msg3 PUSCH. On the other hand, for the MsgAPUSCH of the 2-step RACH procedure, the TC-RNTI/C-RNTI may not beapplicable to UEs in the RRC_IDLE or RRC_INACTIVE state. Accordingly,according to various embodiments, an RNTI (e.g., RA-RNTI) different fromthe TC-RNTI/C-RNTI may be applied as n_(RNTI). According to variousembodiments, the C-RNTI may be applied as n_(RNTI) to the UE in theRRC_CONNECTED state.

In the 4-step RACH procedure, N_(ID) ^(cell) (physical cell identifier(PCI)) may be applied as n_(ID) for the Msg3 PUSCH. On the other hand,for the MsgA PUSCH of the 2-step RACH procedure, multiple RAPIDs may bemapped to one PO. In this case, for example, inter-layer interferencebetween PUSCH data REs may increase. According to various embodiments,to reduce the interference, a plurality of scrambling sequencesgenerated by different values of n_(ID) may be applied instead of N_(ID)^(cell) (applied for UL MIMO). According to various embodiments, in thecase of CBRA, an RAPID may be applied as n_(ID) for the MsgA PUSCH.According to various embodiments, in the case of CBRA, the RAPID andC-RNTI may be applied as seed values for sequence initialization for theMsgA PUSCH.

According to various embodiments, the PUSCH scrambling sequenceinitialization equation may vary depending on use cases of mappingbetween preambles and PRUs.

According to various embodiments, when one RAPID is mapped to aplurality of PRUs in a PO, a PUSCH scrambling sequence initializationequation based on DMRS indices may be used instead of that based onRAPIDs.

According to various embodiments, when one RAPID is mapped to multiplePRUs in each PO, the PUSCH scrambling sequence initialization equationbased on RAPIDs may be used.

According to various embodiments, an initialization ID for MsgA PUSCHscrambling may be defined as shown in Equation 2 below.c _(init)=RA−RNTI×2¹⁶+RAPID×2¹⁰ +n _(ID)  [Equation 2]

For example, C_(init) may denote the initial value of the scramblingsequence generator.

For example, n_(ID) may be configured by a cell-specific higher layerparameter, and/or n_(ID)=N_(ID) ^(cell).

According to various embodiments, the RAPID may change or may not changeto the DMRS index.

According to various embodiments, one-to-multiple mapping betweenpreambles and PRUs may be supported and/or may not be supported.

According to various embodiments, for one-to-multiple mapping, thefollowing two cases may be considered:

-   -   1) Case 1: One RAPID may be mapped to multiple PRUs in a PO.    -   2) Case 2: One RAPID may be mapped to multiple PRUs in each PO.

For example, including an RAPID in the equation (Equation 1, etc.) forinitializing a scrambling sequence may be to improve an inter-userinterference randomization effect on PUSCH resources.

In Case 1, if multiple UEs that have selected the same RAPID transmitPUSCHs with the same scrambling sequence, the BS may not obtain theinter-user interference randomization effect.

In Case 2, the BS may obtain the inter-user interference randomizationeffect according to the equation (Equation 1, etc.) for initializing thescrambling sequence.

According to various embodiments, whether the equation (Equation 1,etc.) for initializing a scrambling sequence including an RAPID is usedmay be determined depending on which one of the cases is selected forone-to-multiple mapping.

In Case 1, the RAPID may change to the DMRS index.

In Case 2, the RAPID may be used as it is.

For example, a scrambling sequence generator used to generate a PUSCH(or a scrambling sequence generator for a PUSCH) may be initializedaccording to Equation 3 below. At least one of the parameters used inEquation 3 below may be generated/obtained/determined according tovarious embodiments. Equation 3 may be understood as an equation morespecific than Equation 2.

$\begin{matrix}{c_{init} = \left\{ \begin{matrix}{{n_{RNTI} \cdot 2^{16}} + {n_{RAPID} \cdot 2^{10}} + n_{ID}} & {{for}\ {msg}A{on}{}{PUSCH}} \\{{n_{RNTI} \cdot 2^{15}} + n_{ID}} & {otherwise}\end{matrix} \right.} & \left\lbrack {{Equation}3} \right\rbrack\end{matrix}$

For example, C_(init) may denote the initial value of the scramblingsequence generator.

For example, the value of each parameter may be determined as follows.

-   -   If the RNTI is a C-RNTI, a modulation and coding scheme C-RNTI        (MCS-C-RNTI), a semi-persistent channel state information RNTI        (SP-CSI-RNTI), or a configured scheduling RNTI (CS-RNTI), if        (PUSCH) transmission is not scheduled by DCI format 1_0 in a        CSS, and if a higher layer parameter dataScramblingIdentityPUSCH        is configured, n_(ID)∈{0, 1, . . . , 1023} may have a value        indicated in the higher layer parameter        dataScramblingIdentityPUSCH.    -   If (PUSCH) transmission is triggered by the Type-2 random access        procedure (2-step RACH procedure) and if a higher layer        parameter msgA-dataScramblingIdentity is configured, n_(ID)∈{0,        1, . . . , 1023} may have a value indicated by the higher layer        parameter msgA-dataScramblingIdentity.    -   Otherwise, n_(ID)=N_(ID) ^(cell). That is, n_(ID) may have the        same value as a PCI. For example, n_(ID) may have a value of 0        to 1007.    -   n_(RAPID) may be the index of a random access preamble        transmitted for MsgA. For example, n_(RAPID) may correspond to        information related to a PRACH preamble selected by the UE (or        user) as the seed value of the scrambling sequence, and the user        may be identified by n_(RAPID).    -   n_(RNTI) may have the same value as an RA-RNTI for MsgA (for a        PUSCH included in MsgA). For example, n_(RNTI) may be the seed        value of the scrambling sequence, and more particularly,        n_(RNTI) may correspond to an RNTI used to monitor a response        (from the BS) for the above-described RA-RNTI or MsgA PUSCH. As        another example, n_(RNTI) may have the same value as an RA-RNTI        for the 4-step RACH procedure.

For example, inter-cell interference may be randomized by n_(ID).

In the 2-step RACH procedure, there may be an RA-RNTI and a MsgB-RNTIrelated to a specific RO.

According to various embodiments, the RA-RNTI may be used togenerate/obtain a PUSCH data scrambling sequence, and the MsgB-RNTI maybe used to monitor a PDCCH for MsgB.

That is, according to various embodiments, the usage of the RA-RNTI andMsgB-RNTI related to the specific RO may be distinguished.

In addition, according to various embodiments, the RA-RNTI bedistinguished from the RAPID and used as the seed value forgenerating/obtaining the PUSCH data scrambling sequence.

Supported MCS and Time-Frequency Resource Size of PUSCH in MsgA

According to various embodiments, a limited number of MCS levels may beused for a PUSCH in MsgA. For example, one and/or two MCS levels may beused.

According to various embodiments, only QPSK for CP-OFDM may be appliedfor the PUSCH in MsgA.

According to various embodiments, two types of coding rates may be used.

According to various embodiments, the MCS may be indicated only for aPUSCH configuration. According to various embodiments, among the MCS fora MsgA PUSCH and RRC for a TBS, only the MCS may be signaled. Accordingto various embodiments, the TBS may be determined based on apredetermined correspondence relationship with the MCS value by apredetermined TBS table. According to various embodiments, the valuerange of the TBS and/or MCS may be preconfigured.

According to various embodiments, the modulation order and/or codingrate for the MsgA PUSCH may be provided.

In the 4-step RACH procedure, the MCS for Msg3 may beallocated/indicated by a UL grant in an RAR message. For example, the BSmay designate the MCS from a low index to a high index depending on thechannel state of the UE. For example, time/frequency resources for aPUSCH may be allocated depending on the selected MCS level and requiredcoverage.

On the other hand, in the 2-step RACH procedure, it may be difficult toallow flexible MCS selection. If the UE selects an MCS level for ULtransmission depending on DL measurement results, it may be difficult toapply the MCS level to UL transmission because the channel state as wellas the interference level may significantly vary between DL and ULchannels. In addition, the amount of resources required for the MsgAPUSCH may vary depending on the MCS level.

That is, if multiple MCS levels are allowed, many types of PUSCHresources may be defined and/or pre-assigned, which may not be good interms of resource utilization.

According to various embodiments, an extremely limited number of MCSlevels may be used for the PUSCH in MsgA. For example, one and/or twoMCS levels may be used. According to various embodiments, only QPSK forCP-OFDM may be applied for the PUSCH in MsgA. According to variousembodiments, two types of coding rates may be used.

According to various embodiments, when multiple sets for DMRS frequencyresources are allowed, each DMRS frequency resource (e.g., CDM group)may be configured by a MsgA PUSCH configuration.

According to various embodiments, when multiple MCS levels are allowedfor PUSCH transmission, multiple types of PUSCH resources may beconfigured by the MsgA PUSCH configuration depending on the MCS level.

According to various embodiments, a value range configured byssb-perRACH-OccasionAndCB-PreamblesPerSSB-msgA(msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB) may be divided into Nparts (where N is a natural number). According to various embodiments, apart of the value range may consist of a set of RAPIDs, which may beassociated with MsgA PUSCH configuration(s). In addition, according tovarious embodiments, other parts of the value range may be associatedwith other MsgA PUSCH configurations.

According to various embodiments,msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB may be included inRACH-ConfigCommonTwoStepRA used to specify cell-specific parameters forthe 2-step RACH procedure.

According to various embodiments,msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB may be defined as shownin Table 15 below.

TABLE 15 msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB The meaning ofthis field is twofold: the CHOICE conveys the information about thenumber of SSBs per RACH occasion. Value oneEight corresponds to one SSBassociated with 8 RACH occasions, value oneFourth corresponds to one SSBassociated with 4 RACH occasions, and so on. The ENUMERATED partindicates the number of Contention Based preambles per SSB. Value n4corresponds to 4 Contention Based preambles per SSB, value n8corresponds to 8 Contention Based preambles per SSB, and so on. Thetotal number of CB preambles in a RACH occasion is given byCB-preambles-per-SSB ⁺ max(1. SSB- per-rach-occasion). If the field isnot configured and both 2-step and 4-step are configured for the BWP,the UE applies the value in the fieldssb-perRACH-OccasionAndCB-PreamblesPerSSB in RACH-ConfigCommon. Thefield is not present when RACH occasions are shared between 2-step and4-step type random access in the BWP.

According to various embodiments, when multiple MCS levels are allowedfor PUSCH transmission, multiple types of PUSCH resources may be defineddepending on MCS levels. As a result, according to various embodiments,when a PUSCH resource is associated/related to a RAPID, the RAPID mayalso be associated/related to an MCS level. Accordingly, according tovarious embodiments, if the UE determines an appropriate MCS level forPUSCH transmission, the UE may select the RAPID associated with the MCSlevel.

According to various embodiments, if multiple sets of DMRS frequencyresources are allowed, each DMRS frequency resource may be defined inassociation with an MCS level.

For example, assuming two different PUSCH resources (e.g., a firstlarger frequency resource (set) for a lower MCS level and a secondsmaller frequency resource (set) for a higher MCS level), two differentfrequency resource sets may be designated for each PUSCH resource.

FIG. 20 is a diagram illustrating an exemplary resource configurationfor MsgA according to various embodiments. Specifically, FIG. 20illustrates an example of designating a DMRS RE depending on a PUSCHresource and an MCS level according to various embodiments.

Referring to FIG. 20 , for example, when a relatively high MCS level isused for a PUSCH included in MsgA, a relatively small frequency resourceconsisting of one RB may be used for the PUSCH included in MsgA. Thatis, when a relatively high MCS level is used for a PUSCH included inMsgA, the PUSCH included in MsgA may be allocated to a relatively smallfrequency resource consisting of one RB.

For example, when a relatively low MCS level is used for a PUSCHincluded in MsgA, a relatively large frequency resource consisting oftwo RBs may be used for the PUSCH included in MsgA. That is, when arelatively low MCS level is used for a PUSCH included in MsgA, the PUSCHincluded in MsgA may be allocated to a relatively large frequencyresource consisting of two RBs.

For example, a first comb including a set of REs each having an evenindex and a second comb including a set of REs each having an odd indexmay be configured.

For example, when a relatively high MCS level is used for a PUSCHincluded in MsgA, a DMRS may be allocated to the first comb.

In addition, when a relatively low MCS level is used for a PUSCHincluded in MsgA, a DMRS may be allocated to the 2nd comb.

That is, a DMRS resource (e.g., a DMRS port) for a PUSCH included inMsgA may be determined based on the MCS level.

Alternatively, for multiple PUSCH configurations having overlapped DMRSsymbols, the BS (and/or network) may allocate a different CDM group toeach MsgA PUSCH configuration.

According to various embodiments, at least two MsgA PUSCH configurationsmay be supported. According to various embodiments, parameters (e.g., anMCS, an MCS/TBS, an antenna port/sequence, a time/frequency resource fora PO, a duration/slot offset for a PO group, etc.) may be configuredindependently for each MsgA PUSCH configuration. According to variousembodiments, allowing multiple configurations may be to configuredifferent MCS levels and/or different time/frequency resources.Additionally/alternatively, according to various embodiments, adifferent period/offset may be configured for each MsgA PUSCHconfiguration.

On the other hand, if the number of valid POs in the time domain varies,MsgA preamble-to-PRU mapping may become more difficult. Accordingly,according to various embodiments, POs configured by different MsgA PUSCHconfigurations may be located at least at the same time position.

According to various embodiments, the configured POs may overlap in thetime/frequency domain. According to various embodiments, if a differentCDM group is configured for each PO, the network may separate multipleUL signals transmitted on time/frequency resources (see FIG. 20 ).

PUSCH Configuration Indication

According to various embodiments, a preamble group in CBRA may be usedfor both MsgA PUSCH indication and preamble group indication.

-   -   For example, if preamble groups A and B are used for the 2-step        RACH procedure, these preamble groups may be used to indicate        both a MsgA PUSCH configuration and a preamble group.        -   For example, the UE may select a preamble group depending on            the message size for transmission.    -   For example, if preamble groups A and B are not configured for        the 2-step RACH procedure, these preamble groups may be used        only to indicate a MsgA PUSCH configuration.        -   For example, the UE may select a preamble group depending on            the channel state (e.g., synchronization signal reference            signal received power (SS-RSRP)).

According to various embodiments, a value range configured byssb-perRACH-OccasionAndCB-PreamblesPerSSB-msgA(msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB) may be divided into Nparts (where N is a natural number). According to various embodiments, apart of the value range may consist of a set of RAPIDs, which may beassociated with a MsgA PUSCH configuration. According to variousembodiments, other parts of the value range may be associated with otherPUSCH configurations.

According to various embodiments, a method of indicating selection ofdifferent PUSCH configurations may be provided.

According to various embodiments, for two configurations, differentpreamble groups may be used to indicate different configurations.

According to various embodiments, the maximum number of configurationsmay be defined as follows:

-   -   In REL. 16, two or more MsgA PUSCH configurations may not be        supported for the UE in the RRC_IDLE/INACTIVE state.    -   For the UE in the RRC_ACTIVE state:        -   A maximum of two MsgA PUSCH configurations may be supported            in a UL BWP.            -   When no MsgA PUSCH configuration is configured for the                UL BWP, the initial BWP configuration may be applied.            -   A preamble group-based method defined for the                RRC_IDLE/INACTIVE state may be used.            -   The number of MsgA PUSCH configurations may or may not                be equal to that for the UE in the RRC_IDLE/INACTIVE                state.            -   At least one of PRACH configuration(s) or MsgA PUSCH                configuration(s) may be BWP-specific and/or                cell-specific.

According to various embodiments, preamble groups A and B may beintroduced for the for 2-step RACH procedure.

According to various embodiments, selection formulas for the 4-step RACHprocedure of REL. 15 may be used for selection one of the 2-step RACHpreamble groups: preamble groups A and B.

According to various embodiments, a parameter ra-MsgASizeGroupA(ra-MsgA-SizeGroupA) may be introduced for a data threshold,

According to various embodiments, ra-MsgASizeGroupA (ra-MsgA-SizeGroupA)may be defined as shown in Table 16 below.

TABLE 16 ra-MsgA-SizeGroupA Transport block size threshold in bits belowwhich the UE shall use a contention-based RA preamble of group A. (seeTS 38.321 [3], clause 5.1.1).

According to various embodiments, two preamble groups (e.g., group A andgroup B) in CBRA may be used to indicate the message size.

According to various embodiments, when preamble groups A and B areactivated, a preamble group may be aligned with a PUSCH configuration.According to various embodiments, depending on the TB S size forpreamble groups A and B, time/frequency resources of different sizes maybe allocated for each PUSCH in different PUSCH configurations. Accordingto various embodiments, the UE may select a preamble group and a PUSCHconfiguration depending on the TBS size to be transmitted.

According to various embodiments, when the network does not operatepreamble groups A and B, a preamble group may be used only to indicate aPUSCH configuration. According to various embodiments, since aconfigured PUSCH resource may have different MCS levels for the same TBSsize, the UE may select a preamble group depending on the channel state(e.g., based on RSRP, etc.).

Intra-Slot Frequency Hopping and Guard Band

According to various embodiments, intra-slot hopping (in-slot hopping)may be established without a guard period in a PO.

According to various embodiments, intra-slot hopping may be supportedfor a MsgA PUSCH.

According to various embodiments, a PRB-level guardband configurationbetween frequency division multiplexed (FDMed) POs each consisting ofPRB values {0, 1} may be supported.

According to various embodiments, intra-slot hopping per PO for MsgA maybe configured based on a configuration per MsgA.

-   -   According to various embodiments, the hopping pattern may be        based on the Msg3 hopping pattern of REL. 15.    -   According to various embodiments, a UL-BWP specific parameter        may be used.    -   According to various embodiments, a guard period between hops        may or may not be used.    -   According to various embodiments, POs may be continuous and/or        discontinuous in time.

According to various embodiments, an inter-hop guard period may or maynot be used. According to various embodiments, the use of a guard periodbetween hops may or may not be allowed.

According to various embodiments, a frequency diversity gain may beobtained from slot hopping.

For example, if a guard time is configured, the duration of the guardtime may be required twice within a PO. For example, compared tofrequency diversity gain and energy loss, intra-slot hopping may notprovide a performance gain. Thus, according to various embodiments, slothopping may be configured in a PO without any guard periods.

3.3. Mapping for RACH Preamble and PUSCH Resource

RO Mapping/RACH Preamble Configuration for 2-Step RACH

According to various embodiments, an RO may be configured/mapped basedon whether RO sharing is allowed between the 2-step RACH procedure and4-step RACH procedure.

According to various embodiments, for RO separation between the 2-stepRACH procedure and 4-step RACH procedure, a configuration for using asubset of ROs in a slot may be allowed.

According to various embodiments, for RO separation between the 2-stepRACH procedure and 4-step RACH procedure, a configuration for using anOFDM symbol in a first RACH half slot as an RO may be allowed.

According to various embodiments, a parameter for updating/reconfiguringthe value of a parameter configured by a RACH configuration may beintroduced. For example, parameters for updating/reconfiguring thenumber of ROs in a slot, the start OFDM symbol, etc. may be introduced.

For example, ROs may be shared between the 2-step RACH procedure and the4-step RACH procedure. For example, a PRACH preamble for the 4-step RACHprocedure and a PRACH preamble for the 2-step RACH procedure may beseparately configured/designated. For example, in both cases where ROsharing is allowed and is not allowed, the PRACH preamble for the 4-stepRACH procedure and the PRACH preamble for the 2-step RACH procedure maybe separately configured/designated.

For example, if 64 PRACH preambles are allocated for thecontention-based RACH procedure, it may be configured/indicated that thefirst 32 PRACH preambles are PRACH preambles for the 4-step RACHprocedure and the last 32 PRACH preambles are PRACH preambles for the2-step RACH procedure. For example, the correspondingconfiguration/indication may be based on SIB1 and/or a RACHconfiguration included in UE-specific RRC signaling.

For example, a PRACH preamble may be understood as a code-domainresource, which may be identified by the root index of the preamble. Forexample, upon receiving a PRACH preamble, the BS may check whether thecorresponding PRACH preamble is a PRACH preamble for the 4-step RACHprocedure and/or a PRACH preamble for the 2-step RACH procedure so thatthe BS may recognize whether the UE transmitting the PRACH preambledesires to initiates the 2-step RACH procedure or the 4-step RACHprocedure.

On the other hand, if RO sharing is not allowed (that is, for ROseparation), ROs for the 4-step RACH procedure and ROs for the 2-stepRACH procedure may be separated. In this case, the BS may recognizebased on the corresponding RO whether the UE transmitting a PRACHpreamble desires to initiate the 2-step RACH procedure or the 4-stepRACH procedure based on the corresponding RO.

According to various embodiments, among PRACH preambles (except forPRACH preamble(s) for the 4-step RACH procedure) within an RO configuredfor the (contention-based) 4-step RACH procedure, PRACH preamble(s) maybe configured for the (contention-based) 2-step RACH procedure.According to various embodiments, the BS may identify the purpose ofPRACH transmission (for example, whether the PRACH transmission is forthe 2-step RACH procedure or 4-step RACH procedure). According tovarious embodiments, since PRACH preambles are separated into PRACHpreambles for the 2-step RACH procedure and PRACH preambles for the4-step RACH procedure, the BS may determine based on a PRACH preamblewhether PRACH transmission is for the 2-step RACH procedure or 4-stepRACH procedure.

According to various embodiments, for RO sharing, a PUSCH in MsgA may beallocated to a PUSCH slot after a RACH slot.

According to various embodiments, when RO sharing is not allowed, an ROfor the 2-step RACH procedure may be configured. According to variousembodiments, at least one of the following two methods may be consideredto configure the RO for the 2-step RACH procedure:

-   -   1) Slot level TDM/slot level multiplexing: according to various        embodiments, RACH configuration tables for the 4-step RACH        procedure may be reused. For example, the RACH configuration        tables may be designed on the assumption that most of OFDM        symbols in a RACH slot or second RACH half slot are used as an        RO. Accordingly, in this case, an RO and a PUSCH may be        multiplexed in different slots.    -   2) Symbol level TDM)/symbol level multiplexing: according to        various embodiments, OFDM symbol(s) in a first RACH half slot        may be configured to be used as an RO. According to various        embodiments, OFDM symbols after the RO may be allocated for a        PUSCH of MsgA.

FIG. 21 is a diagram illustrating an exemplary MsgA configurationaccording to various embodiments. Specifically, FIG. 21 shows anexemplary method in which an RO for MsgA and a PUSCH for MsgA aremultiplexed at the slot level.

Referring to FIG. 21 , an RO for transmitting a PRACH preamble includedin MsgA and a PO for transmitting a PUSCH included in MsgA may be timedivision multiplexed (TDMed) at the slot level.

For example, the RO may be included in or mapped to a RACH slotpositioned earlier than a PUSCH slot in the time domain In addition, thePO may be included in or mapped to the PUSCH slot positioned after theRACH slot in the time domain.

For example, each of the RO and/or PO may be multiplexed in each slot invarious ways.

FIG. 21 (a) illustrates an example in which ROs are TDMed in a RACH slotand PUSCHs are FDMed/TDMed in a PUSCH slot.

FIG. 21(b) illustrates an example in which ROs are FDMed/TDMed in a RACHslot and PUSCHs are FDMed in a PUSCH slot.

FIG. 21(c) illustrates an example in which ROs are FDMed in a RACH slotand PUSCHs are TDMed in a PUSCH slot.

FIG. 21(d) illustrates an example in which ROs are TDMed in a RACH slotand PUSCHs are TDMed/CDMed in a PUSCH slot.

A prescribed time offset may be set between an RO and a PO in the timedomain That is, the prescribed time offset may be configured between aRACH slot including the RO and a PUSCH slot including the PO in the timedomain.

For example, the corresponding time offset may consist of apredetermined number of slots.

As an opposite example, when no time offset is configured, the RACH slotand the PUSCH slot may be contiguous in the time domain.

FIG. 22 is a diagram illustrating an exemplary MsgA configurationaccording to various embodiments. Specifically, FIG. 22 shows anexemplary method in which an RO for MsgA and a PUSCH for MsgA aremultiplexed at the symbol level.

Referring to FIG. 22 , an RO for transmitting a PRACH preamble includedin MsgA and a PO for transmission a PUSCH included in MsgA may be TDMedat the symbol level

For example, the RO and PO may be included in one slot.

For example, the RO may be included in or mapped to a RACH half-slotlocated earlier than a PUSCH half-slot in the time domain. In addition,the PO may be included in or mapped to the PUSCH half-slot located afterthe RACH half-slot in the time domain.

For example, the RO may be included in or mapped to one or more OFDMsymbols in the RACH half-slot. In addition, the PO may be included in ormapped to one or more OFDM symbols in the PUSCH half-slot.

For example, each of the RO and/or PO may be multiplexed within eachhalf-slot in various ways.

FIG. 22 (a) illustrates an example in which one RO is configured in aRACH half-slot and PUSCHs are FDMed in a PUSCH half-slot.

FIG. 22(b) illustrates an example an example in which ROs are FDMed in aRACH half-slot and PUSCHs are TDMed in a PUSCH half-slot.

FIG. 22(c) illustrates an example an example in which ROs are TDMed in aRACH half-slot and PUSCHs are FDMed/TDMed in a PUSCH half-slot.

FIG. 22(d) illustrates an example an example in which ROs areFDMed/TDMed in a RACH half-slot and PUSCHs are TDMed/CDMed in a PUSCHhalf-slot.

RACH Preamble-To-PRU Mapping for 2-Step RACH and/or Periodicity Thereof

According to various embodiments, the (RACH preamble-to-PRU) mapping maybe defined between a MsgA RO in period A and a MsgA PO in period B.

-   -   According to various embodiments, period B may be determined        based on an SSB-to-RACH association period. For example, period        B has the same duration (length) as period A, but the starting        point thereof may be shifted by a single offset of a MsgA PUSCH        configuration.

According to various embodiments, period A may be determined based onthe SSB-to-RACH association period. For example, since the number ofvalid MsgA ROs is identified within the SSB-to-RO association period,period A may be the same as the SSB-to-RACH association period.

According to various embodiments, preambles in available/valid ROs of aRACH slot in front of available/valid POs may be mapped to PRUs withinthe available/valid POs.

According to various embodiments, an association period for SSB-to-ROmapping may be applied to RACH preamble-to-PRU mapping. According tovarious embodiments, preambles in available/valid ROs in an associationperiod for SSB-to-RO mapping may be mapped to PRUs in an available/validPOs in the association period.

According to various embodiments, a single offset value for indicatingthe location of a PO group may be allowed. According to variousembodiments, if the periodicity of a RACH is the same as that of a POgroup, each RACH slot may be mapped to the PO group.

According to various embodiments, a mapping rule between RACH preamblesand PRUs may be defined as follows:

-   -   0) A validation check which POs are available.    -   1) Preambles in available ROs of a RACH slot in front of        available POs may be mapped to PRUs in the available POs.    -   2) Preambles in available ROs in period A may be mapped to PRUs        in available POs in period B.        -   A) (one-to-one mapping) If the number of preambles for CBRA            in available ROs in period A is the same as the number of            PRUs in available POs in period B, all preambles for CBRA            may be mapped to all PRUs.        -   B) (many-to-one mapping) If the number of preambles for CBRA            in available ROs in period A is greater than the number of            PRUs in available POs in period B, all preambles for CBRA            may be mapped to all PRUs and/or a subset thereof. When a            subset of PRUs is used, the remaining PRUs may not be used            for the 2-step RACH procedure.        -   C) (one-to-one mapping with multiple cycles) When the number            of preambles for CBRA in available ROs in period A is            smaller than the number of PRUs in available POs in period            B, all preambles for CBRA may be mapped to all PRUs and/or a            subset thereof. When a subset of PRUs is used, the remaining            PRUs may not be used for the 2-step RACH procedure.        -   If a set of (a number of) actually transmitted SSBs (ATSSs)            mapped to ROs in an SSB-to-RO association period are not            fully mapped with PRUs in available POs in period B,            preambles in available ROs may not be mapped to the PRUs in            the available POs.        -   The remaining preambles for the 2-step RACH procedure, which            are not mapped to the PRUs, may be used for MsgA preamble            only transmission.    -   In many-to-one mapping, consecutive PRACH preambles (N        consecutive PRACH preamble indexes) may be mapped to the same        PRU, and then next consecutive PRACH preamble (N consecutive        PRACH preamble indexes) may be mapped to the next PRU.

For example, an association period for SS/PBCH block-to-PRACH occasionmapping, which starts from frame 0, may be equivalent to a minimum valuein a set determined by a PRACH configuration period according to Table17.

TABLE 17 PRACH configuration Association period (number of period (msec)PRACH configuration periods) 10 {1, 2, 4, 8, 16} 20 {1, 2, 4, 8} 40 {1,2, 4} 80 {1, 2} 160  {1}

For example, a predetermined number of SS/PBCH blocks obtained from thevalue of ssb-PositionsInBurst indicating ATSSs included in SIB1 and/orServingCellConfigCommon (which is an IE used to configure cell-specificparameters of the serving cell of the UE) may be mapped to one or morePRACH occasions within an association period. For example, thepredetermined number of SS/PBCH blocks may be cyclically mapped to PRACHoccasions a predetermined integer number of times within the associationperiod. For example, an association pattern period may include one ormore association periods, and a pattern between PRACH occasions andSS/PBCH indices may be determined to be repeated at most every 160 ms.

For a paired spectrum, all PRACH occasions may be valid.

For an unpaired spectrum:

-   -   When the UE is not provided tdd-UL-DL-ConfigurationCommon, if a        PRACH occasion in a PRACH slot does not precede a SS/PBCH block        in the PRACH slot and starts at least N symbols after the last        SS/PBCH block reception symbol (where N is an integer or natural        number), if ChannelAccessMode-r16=semistatic is provided, and if        the PRACH occasion in the PRACH slot does not overlap a set of        consecutive symbols before the start of a next channel occupancy        time where the UE does not perform transmission, the PRACH        occasion in the PRACH slot may be valid.        -   The candidate SS/PBCH block index of the SS/PBCH block may            correspond to an SS/PBCH block index provided by            ssb-PositionsInBurst.    -   If the UE is provided tdd-UL-DL-ConfigurationCommon, a PRACH        occasion in a PRACH slot may be valid if at least one of the        following conditions are satisfied:        -   If the PRACH occasion in the PRACH slot is within UL            symbols; and/or        -   If the PRACH occasion in the PRACH slot does not precede an            SS/PBCH block in the PRACH slot and starts at least N            symbols after the last DL symbol (wherein N is an integer or            natural number) or starts at least N symbols after the last            SS/PBCH block reception symbol (wherein N is an integer or            natural number), if ChannelAccessMode-r16=semistatic is            provided, and if the PRACH occasion in the PRACH slot does            not overlap with a set of consecutive symbols before the            start of a next channel occupancy time where no transmission            is performed.        -   The candidate SS/PBCH block index of the SS/PBCH block may            correspond to an SS/PBCH block index provided by            ssb-PositionsInBurst.

FIG. 23 is a diagram illustrating exemplary time-domain locations for aMsgA RACH and a MsgA PUSCH according to various embodiments.

In FIG. 23 , it is assumed that a UL slot is allocated every 2.5 ms anda RACH is configured in a subframe with index 9 within a period of 10ms. For example, a PO group may be configured with an offset of 2.5 msand a period of 10 ms.

According to various embodiments, two periods (e.g., association periodsand association pattern periods) for SSB-to-RO mapping may be defineddue to different number of valid ROs within a RACH period.

According to various embodiments, an SSB-to-RO association period may bedetermined by comparing the number of SSBs and the number of valid ROs.Since the number of preambles per SSB is the same, the remaining RACHpreambles in a mapping period may not be mapped to SSBs.

According to various embodiments, for the 2-step RACH procedure,preamble-to-PRU mapping may be provided in consideration of the equalityof the numbers of preambles and PRUs per SSB.

According to various embodiments, for the preamble-to-PRU mapping, itmay be considered that timely closed OFDM symbols are assigned for aMsgA preamble and a MsgA PUSCH in order to reduce the latency.

According to various embodiments, when valid MsgA ROs in period A andvalid MsgA POs in period B are determined, the preamble-to-PRU mappingmay operate.

According to various embodiments, period A may be determined based on anSSB-to-RACH association period. For example, since the number of validMsgA ROs is identified within an SSB-to-RO association period, period Amay be equivalent to the SSB-to-RACH association period.

According to various embodiments, a mapping rule between RACH preamblesand PRUs may be defined as follows:

-   -   0) A validation check which POs are available.        -   A) POs in a flexible/UL slot may be available.        -   B) POs after a gap period of N symbols (where N is an            integer greater than or equal to 0 or a natural number) from            the last DL symbol may be available.        -   C) POs that do not collide with an SSB may be available.    -   1) Preambles in available ROs of a RACH slot in front of        available POs may be mapped to PRUs in the available POs.    -   2) An SSB-to-RO association period may be applied to RACH        preamble-to-PRU mapping.        -   A) Preambles in available ROs in the association period for            SSB-to-RO mapping may be mapped to PRUs in available POs in            the association period.    -   3) If the number of preambles for CBRA in available ROs in the        association period is equal to or greater than the number of        PRUs in available POs in the association period, all preambles        for CBRA or a subset of preambles may be mapped to PRUs in the        available POs.        -   A) If a set of ATSSs mapped to ROs in an association period            for SSB-to-RO mapping are not fully mapped to PRUs in            available POs in an SSB association period, preambles in            available ROs may not be mapped to available PRUs in the            available POs.        -   B) The remaining preambles for the 2-step RACH procedure,            which are not mapped to the PRUs, may be used for MsgA            preamble only transmission.

Additionally/alternatively, according to various embodiments, a mappingrule between RACH preambles and PRUs may be defined as follows:

-   -   0) A validation check which POs are available.    -   1) Preambles in available ROs of a RACH slot in front of        available POs may be mapped to PRUs in the available POs.    -   2) Preambles in available ROs in period A may be mapped to PRUs        in available POs in period B.        -   A) (one-to-one mapping) If the number of preambles for CBRA            in available ROs in period A is the same as the number of            PRUs in available POs in period B, all preambles for CBRA            may be mapped to all PRUs.        -   B) (many-to-one mapping) If the number of preambles for CBRA            in available ROs in period A is greater than the number of            PRUs in available POs in period B, all preambles for CBRA            may be mapped to all PRUs and/or a subset thereof. When a            subset of PRUs is used, the remaining PRUs may not be used            for the 2-step RACH procedure.        -   C) (one-to-one mapping with multiple cycles) When the number            of preambles for CBRA in available ROs in period A is            smaller than the number of PRUs in available POs in period            B, all preambles for CBRA may be mapped to all PRUs and/or a            subset thereof. When a subset of PRUs is used, the remaining            PRUs may not be used for the 2-step RACH procedure.        -   If a set of (a number of) ATSSs mapped to ROs in an            SSB-to-RO association period are not fully mapped with PRUs            in available POs in period B, preambles in available ROs may            not be mapped to the PRUs in the available POs.        -   The remaining preambles for the 2-step RACH procedure, which            are not mapped to the PRUs, may be used for MsgA preamble            only transmission.    -   In many-to-one mapping, consecutive PRACH preambles (N        consecutive PRACH preamble indexes) may be mapped to the same        PRU, and then next consecutive PRACH preamble (N consecutive        PRACH preamble indexes) may be mapped to the next PRU. That is,        each of the N consecutive PRACH preamble indexes of valid PRACH        occasions in a PRACH slot may be mapped to one PO (and DMRS        resource associated therewith). According to various        embodiments, the number N of consecutive PRACH preamble indexes        may be determined based on the number of valid PRACH occasions        and the number of valid POs.

FIG. 24 is a diagram schematically illustrating a method of operating aUE and a BS according to various embodiments.

FIG. 25 is a flowchart illustrating a method of operating a UE accordingto various embodiments.

FIG. 26 is a flowchart illustrating a method of operating a BS accordingto various embodiments.

FIGS. 24 to 26 , in operations 2401 and 2501 according to variousembodiments, the UE may obtain/generate MsgA. According to variousembodiments, MsgA may include a PRACH preamble and a PUSCH.

In operations 2403, 2503, and 2603 according to various embodiments, theUE may transmit MsgA, and the BS may receive MsgA.

In operations 2405 and 2605 according to various embodiments, the BS mayobtain the PRACH preamble and the PUSCH based on MsgA.

According to various embodiments, the PUSCH may be transmitted/receivedbased on received/transmitted information related to a PUSCHconfiguration for MsgA.

According to various embodiments, based on that the information relatedto the PUSCH configuration includes information related to indication ofa CDM group for a DMRS for the PUSCH, the CDM group may be configured asa group indicated by the information related to the indication of theCDM group of two predetermined groups.

Since examples of the above-described proposal method may also beincluded in one of implementation methods of the various embodiments ofthe present disclosure, it is obvious that the examples are regarded asa sort of proposed methods. Although the above-proposed methods may beindependently implemented, the proposed methods may be implemented in acombined (aggregated) form of a part of the proposed methods. A rule maybe defined such that the BS informs the UE of information as to whetherthe proposed methods are applied (or information about rules of theproposed methods) through a predefined signal (e.g., a physical layersignal or a higher-layer signal).

4. Exemplary Configurations of Devices Implementing Various Embodimentsof the Present Disclosure 4.1. Exemplary Configurations of Devices towhich Various Embodiments of the Present Disclosure are Applied

FIG. 28 is a diagram illustrating devices that implement variousembodiments of the present disclosure.

The devices illustrated in FIG. 28 may be a UE and/or a BS (e.g., eNB orgNB) adapted to perform the afore-described mechanisms, or any devicesperforming the same operation.

Referring to FIG. 28 , the device may include a digital signal processor(DSP)/microprocessor 210 and a radio frequency (RF) module (transceiver)235. The DSP/microprocessor 210 is electrically coupled to thetransceiver 235 and controls the transceiver 235. The device may furtherinclude a power management module 205, a battery 255, a display 215, akeypad 220, a SIM card 225, a memory device 230, an antenna 240, aspeaker 245, and an input device 250, depending on a designer'sselection.

Particularly, FIG. 28 may illustrate a UE including a receiver 235configured to receive a request message from a network and a transmitter235 configured to transmit timing transmission/reception timinginformation to the network. These receiver and transmitter may form thetransceiver 235. The UE may further include a processor 210 coupled tothe transceiver 235.

Further, FIG. 28 may illustrate a network device including a transmitter235 configured to transmit a request message to a UE and a receiver 235configured to receive timing transmission/reception timing informationfrom the UE. These transmitter and receiver may form the transceiver235. The network may further include the processor 210 coupled to thetransceiver 235. The processor 210 may calculate latency based on thetransmission/reception timing information.

A processor included in a UE (or a communication device included in theUE) and a BS (or a communication device included in the BS) according tovarious embodiments of the present disclosure may operate as follows,while controlling a memory.

According to various embodiments of the present disclosure, a UE or a BSmay include at least one transceiver, at least one memory, and at leastone processor coupled to the at least one transceiver and the at leastone memory. The at least one memory may store instructions causing theat least one processor to perform the following operations.

A communication device included in the UE or the BS may be configured toinclude the at least one processor and the at least one memory. Thecommunication device may be configured to include the at least onetransceiver, or may be configured not to include the at least onetransceiver but to be connected to the at least one transceiver.

According to various embodiments, the at least one processor included inthe UE (or the at least one processor of the communication deviceincluded in the UE) may obtain MsgA including a PRACH preamble and aPUSCH

According to various embodiments, the at least one processor included inthe UE may transmit MsgA.

According to various embodiments, the PUSCH may be transmitted based onreceived information related to a PUSCH configuration for the message A,

According to various embodiments, based on that the information relatedto the PUSCH configuration includes information related to indication ofa CDM group for a DMRS for the PUSCH, the CDM group may be configured asa group indicated by the information related to the indication of theCDM group of two predetermined groups.

According to various embodiments, the at least one processor included inthe BS (or the at least one processor of the communication deviceincluded in the BS) may receive MsgA.

According to various embodiments, the at least one processor included inthe BS may obtain a PRACH preamble and a PUSCH based on MsgA.

According to various embodiments, the PUSCH may be obtained based ontransmitted information related to a PUSCH configuration for the messageA,

According to various embodiments, based on that the information relatedto the PUSCH configuration includes information related to indication ofa CDM group for a DMRS for the PUSCH, the CDM group may be configured asa group indicated by the information related to the indication of theCDM group of two predetermined groups.

A more specific operation of a processor included in a BS and/or a UEaccording to various embodiments of the present disclosure may bedescribed and performed based on the afore-described clause 1 to clause3.

Unless contradicting with each other, various embodiments of the presentdisclosure may be implemented in combination. For example, the BS and/orthe UE according to various embodiments of the present disclosure mayperform operations in combination of the embodiments of theafore-described clause 1 to clause 3, unless contradicting with eachother.

4.2. Example of Communication System to which Various Embodiments of thePresent Disclosure are Applied

In the present specification, various embodiments of the presentdisclosure have been mainly described in relation to data transmissionand reception between a BS and a UE in a wireless communication system.However, various embodiments of the present disclosure are not limitedthereto. For example, various embodiments of the present disclosure mayalso relate to the following technical configurations.

The various descriptions, functions, procedures, proposals, methods,and/or operational flowcharts of the various embodiments of the presentdisclosure described in this document may be applied to, without beinglimited to, a variety of fields requiring wirelesscommunication/connection (e.g., 5G) between devices.

Hereinafter, a description will be given in more detail with referenceto the drawings. In the following drawings/description, the samereference symbols may denote the same or corresponding hardware blocks,software blocks, or functional blocks unless described otherwise.

FIG. 28 illustrates an exemplary communication system to which variousembodiments of the present disclosure are applied.

Referring to FIG. 28 , a communication system 1 applied to the variousembodiments of the present disclosure includes wireless devices, BaseStations (BSs), and a network. Herein, the wireless devices representdevices performing communication using Radio Access Technology (RAT)(e.g., 5G New RAT (NR)) or Long-Term Evolution (LTE)) and may bereferred to as communication/radio/5G devices. The wireless devices mayinclude, without being limited to, a robot 100 a, vehicles 100 b-1 and100 b-2, an eXtended Reality (XR) device 100 c, a hand-held device 100d, a home appliance 100 e, an Internet of Things (IoT) device 100 f, andan Artificial Intelligence (AI) device/server 400. For example, thevehicles may include a vehicle having a wireless communication function,an autonomous driving vehicle, and a vehicle capable of performingcommunication between vehicles. Herein, the vehicles may include anUnmanned Aerial Vehicle (UAV) (e.g., a drone). The XR device may includean Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality (MR) deviceand may be implemented in the form of a Head-Mounted Device (HMD), aHead-Up Display (HUD) mounted in a vehicle, a television, a smartphone,a computer, a wearable device, a home appliance device, a digitalsignage, a vehicle, a robot, etc. The hand-held device may include asmartphone, a smartpad, a wearable device (e.g., a smartwatch or asmartglasses), and a computer (e.g., a notebook). The home appliance mayinclude a TV, a refrigerator, and a washing machine. The IoT device mayinclude a sensor and a smartmeter. For example, the BSs and the networkmay be implemented as wireless devices and a specific wireless device200 a may operate as a BS/network node with respect to other wirelessdevices.

The wireless devices 100 a to 100 f may be connected to the network 300via the BSs 200. An AI technology may be applied to the wireless devices100 a to 100 f and the wireless devices 100 a to 100 f may be connectedto the AI server 400 via the network 300. The network 300 may beconfigured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g.,NR) network. Although the wireless devices 100 a to 100 f maycommunicate with each other through the BSs 200/network 300, thewireless devices 100 a to 100 f may perform direct communication (e.g.,sidelink communication) with each other without passing through theBSs/network. For example, the vehicles 100 b-1 and 100 b-2 may performdirect communication (e.g. Vehicle-to-Vehicle(V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g.,a sensor) may perform direct communication with other IoT devices (e.g.,sensors) or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, or 150 c may beestablished between the wireless devices 100 a to 100 f/BS 200, or BS200/BS 200. Herein, the wireless communication/connections may beestablished through various RATs (e.g., 5G NR) such as uplink/downlinkcommunication 150 a, sidelink communication 150 b (or, D2Dcommunication), or inter BS communication (e.g. relay, Integrated AccessBackhaul (IAB)). The wireless devices and the BSs/the wireless devicesmay transmit/receive radio signals to/from each other through thewireless communication/connections 150 a and 150 b. For example, thewireless communication/connections 150 a and 150 b may transmit/receivesignals through various physical channels. To this end, at least a partof various configuration information configuring processes, varioussignal processing processes (e.g., channel encoding/decoding,modulation/demodulation, and resource mapping/demapping), and resourceallocating processes, for transmitting/receiving radio signals, may beperformed based on the various proposals of the various embodiments ofthe present disclosure.

4.2.1 Example of Wireless Devices to which Various Embodiments of thePresent Disclosure are Applied

FIG. 29 illustrates exemplary wireless devices to which variousembodiments of the present disclosure are applicable.

Referring to FIG. 29 , a first wireless device 100 and a second wirelessdevice 200 may transmit radio signals through a variety of RATs (e.g.,LTE and NR). Herein, {the first wireless device 100 and the secondwireless device 200} may correspond to {the wireless device 100 x andthe BS 200} and/or {the wireless device 100 x and the wireless device100 x} of FIG. 28 .

The first wireless device 100 may include one or more processors 102 andone or more memories 104 and additionally further include one or moretransceivers 106 and/or one or more antennas 108. The processor(s) 102may control the memory(s) 104 and/or the transceiver(s) 106 and may beconfigured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 102 may process informationwithin the memory(s) 104 to generate first information/signals and thentransmit radio signals including the first information/signals throughthe transceiver(s) 106. The processor(s) 102 may receive radio signalsincluding second information/signals through the transceiver 106 andthen store information obtained by processing the secondinformation/signals in the memory(s) 104. The memory(s) 104 may beconnected to the processor(s) 102 and may store a variety of informationrelated to operations of the processor(s) 102. For example, thememory(s) 104 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 102or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 102 and the memory(s) 104 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 106 may be connected to the processor(s) 102 andtransmit and/or receive radio signals through one or more antennas 108.Each of the transceiver(s) 106 may include a transmitter and/or areceiver. The transceiver(s) 106 may be interchangeably used with RadioFrequency (RF) unit(s). In the various embodiments of the presentdisclosure, the wireless device may represent a communicationmodem/circuit/chip.

The second wireless device 200 may include one or more processors 202and one or more memories 204 and additionally further include one ormore transceivers 206 and/or one or more antennas 208. The processor(s)202 may control the memory(s) 204 and/or the transceiver(s) 206 and maybe configured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 202 may process informationwithin the memory(s) 204 to generate third information/signals and thentransmit radio signals including the third information/signals throughthe transceiver(s) 206. The processor(s) 202 may receive radio signalsincluding fourth information/signals through the transceiver(s) 106 andthen store information obtained by processing the fourthinformation/signals in the memory(s) 204. The memory(s) 204 may beconnected to the processor(s) 202 and may store a variety of informationrelated to operations of the processor(s) 202. For example, thememory(s) 204 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 202or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 202 and the memory(s) 204 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 206 may be connected to the processor(s) 202 andtransmit and/or receive radio signals through one or more antennas 208.Each of the transceiver(s) 206 may include a transmitter and/or areceiver. The transceiver(s) 206 may be interchangeably used with RFunit(s). In the various embodiments of the present disclosure, thewireless device may represent a communication modem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 100 and 200 willbe described more specifically. One or more protocol layers may beimplemented by, without being limited to, one or more processors 102 and202. For example, the one or more processors 102 and 202 may implementone or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP,RRC, and SDAP). The one or more processors 102 and 202 may generate oneor more Protocol Data Units (PDUs) and/or one or more Service Data Unit(SDUs) according to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document. Theone or more processors 102 and 202 may generate messages, controlinformation, data, or information according to the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document. The one or more processors 102 and 202 maygenerate signals (e.g., baseband signals) including PDUs, SDUs,messages, control information, data, or information according to thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document and provide thegenerated signals to the one or more transceivers 106 and 206. The oneor more processors 102 and 202 may receive the signals (e.g., basebandsignals) from the one or more transceivers 106 and 206 and acquire thePDUs, SDUs, messages, control information, data, or informationaccording to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.

The one or more processors 102 and 202 may be referred to ascontrollers, microcontrollers, microprocessors, or microcomputers. Theone or more processors 102 and 202 may be implemented by hardware,firmware, software, or a combination thereof. As an example, one or moreApplication Specific Integrated Circuits (ASICs), one or more DigitalSignal Processors (DSPs), one or more Digital Signal Processing Devices(DSPDs), one or more Programmable Logic Devices (PLDs), or one or moreField Programmable Gate Arrays (FPGAs) may be included in the one ormore processors 102 and 202. The descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument may be implemented using firmware or software and the firmwareor software may be configured to include the modules, procedures, orfunctions. Firmware or software configured to perform the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be included in the one or more processors102 and 202 or stored in the one or more memories 104 and 204 so as tobe driven by the one or more processors 102 and 202. The descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be implemented using firmware or softwarein the form of code, commands, and/or a set of commands.

The one or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 and store various types of data, signals,messages, information, programs, code, instructions, and/or commands.The one or more memories 104 and 204 may be configured by Read-OnlyMemories (ROMs), Random Access Memories (RAMs), Electrically ErasableProgrammable Read-Only Memories (EPROMs), flash memories, hard drives,registers, cash memories, computer-readable storage media, and/orcombinations thereof. The one or more memories 104 and 204 may belocated at the interior and/or exterior of the one or more processors102 and 202. The one or more memories 104 and 204 may be connected tothe one or more processors 102 and 202 through various technologies suchas wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, controlinformation, and/or radio signals/channels, mentioned in the methodsand/or operational flowcharts of this document, to one or more otherdevices. The one or more transceivers 106 and 206 may receive user data,control information, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, from one or moreother devices. For example, the one or more transceivers 106 and 206 maybe connected to the one or more processors 102 and 202 and transmit andreceive radio signals. For example, the one or more processors 102 and202 may perform control so that the one or more transceivers 106 and 206may transmit user data, control information, or radio signals to one ormore other devices. The one or more processors 102 and 202 may performcontrol so that the one or more transceivers 106 and 206 may receiveuser data, control information, or radio signals from one or more otherdevices. The one or more transceivers 106 and 206 may be connected tothe one or more antennas 108 and 208 and the one or more transceivers106 and 206 may be configured to transmit and receive user data, controlinformation, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, through the one ormore antennas 108 and 208. In this document, the one or more antennasmay be a plurality of physical antennas or a plurality of logicalantennas (e.g., antenna ports). The one or more transceivers 106 and 206may convert received radio signals/channels etc. from RF band signalsinto baseband signals in order to process received user data, controlinformation, radio signals/channels, etc. using the one or moreprocessors 102 and 202. The one or more transceivers 106 and 206 mayconvert the user data, control information, radio signals/channels, etc.processed using the one or more processors 102 and 202 from the baseband signals into the RF band signals. To this end, the one or moretransceivers 106 and 206 may include (analog) oscillators and/orfilters.

According to various embodiments of the present disclosure, one or morememories (e.g., 104 or 204) may store instructions or programs which,when executed, cause one or more processors operably coupled to the oneor more memories to perform operations according to various embodimentsor implementations of the present disclosure.

According to various embodiments of the present disclosure, acomputer-readable storage medium may store one or more instructions orcomputer programs which, when executed by one or more processors, causethe one or more processors to perform operations according to variousembodiments or implementations of the present disclosure.

According to various embodiments of the present disclosure, a processingdevice or apparatus may include one or more processors and one or morecomputer memories connected to the one or more processors. The one ormore computer memories may store instructions or programs which, whenexecuted, cause the one or more processors operably coupled to the oneor more memories to perform operations according to various embodimentsor implementations of the present disclosure.

4.2.2. Example of Using Wireless Devices to which Various Embodiments ofthe Present Disclosure are Applied

FIG. 30 illustrates other exemplary wireless devices to which variousembodiments of the present disclosure are applied. The wireless devicesmay be implemented in various forms according to a use case/service (seeFIG. 28 ).

Referring to FIG. 30 , wireless devices 100 and 200 may correspond tothe wireless devices 100 and 200 of FIG. 29 and may be configured byvarious elements, components, units/portions, and/or modules. Forexample, each of the wireless devices 100 and 200 may include acommunication unit 110, a control unit 120, a memory unit 130, andadditional components 140. The communication unit may include acommunication circuit 112 and transceiver(s) 114. For example, thecommunication circuit 112 may include the one or more processors 102 and202 and/or the one or more memories 104 and 204 of FIG. 29 . Forexample, the transceiver(s) 114 may include the one or more transceivers106 and 206 and/or the one or more antennas 108 and 208 of FIG. 29 . Thecontrol unit 120 is electrically connected to the communication unit110, the memory 130, and the additional components 140 and controlsoverall operation of the wireless devices. For example, the control unit120 may control an electric/mechanical operation of the wireless devicebased on programs/code/commands/information stored in the memory unit130. The control unit 120 may transmit the information stored in thememory unit 130 to the exterior (e.g., other communication devices) viathe communication unit 110 through a wireless/wired interface or store,in the memory unit 130, information received through the wireless/wiredinterface from the exterior (e.g., other communication devices) via thecommunication unit 110.

The additional components 140 may be variously configured according totypes of wireless devices. For example, the additional components 140may include at least one of a power unit/battery, input/output (I/O)unit, a driving unit, and a computing unit. The wireless device may beimplemented in the form of, without being limited to, the robot (100 aof FIG. 28 ), the vehicles (100 b-1 and 100 b-2 of FIG. 28 ), the XRdevice (100 c of FIG. 28 ), the hand-held device (100 d of FIG. 28 ),the home appliance (100 e of FIG. 28 ), the IoT device (100 f of FIG. 28), a digital broadcast terminal, a hologram device, a public safetydevice, an MTC device, a medicine device, a fintech device (or a financedevice), a security device, a climate/environment device, the AIserver/device (400 of FIG. 28 ), the BSs (200 of FIG. 28 ), a networknode, etc. The wireless device may be used in a mobile or fixed placeaccording to a use-example/service.

In FIG. 30 , the entirety of the various elements, components,units/portions, and/or modules in the wireless devices 100 and 200 maybe connected to each other through a wired interface or at least a partthereof may be wirelessly connected through the communication unit 110.For example, in each of the wireless devices 100 and 200, the controlunit 120 and the communication unit 110 may be connected by wire and thecontrol unit 120 and first units (e.g., 130 and 140) may be wirelesslyconnected through the communication unit 110. Each element, component,unit/portion, and/or module within the wireless devices 100 and 200 mayfurther include one or more elements. For example, the control unit 120may be configured by a set of one or more processors. As an example, thecontrol unit 120 may be configured by a set of a communication controlprocessor, an application processor, an Electronic Control Unit (ECU), agraphical processing unit, and a memory control processor. As anotherexample, the memory 130 may be configured by a Random Access Memory(RAM), a Dynamic RAM (DRAM), a Read Only Memory (ROM)), a flash memory,a volatile memory, a non-volatile memory, and/or a combination thereof.

Hereinafter, an example of implementing FIG. 30 will be described indetail with reference to the drawings.

4.2.3. Example of Portable Device to which Various Embodiments of thePresent Disclosure are Applied

FIG. 31 illustrates an exemplary portable device to which variousembodiments of the present disclosure are applied. The portable devicemay be any of a smartphone, a smartpad, a wearable device (e.g., asmartwatch or smart glasses), and a portable computer (e.g., a laptop).A portable device may also be referred to as mobile station (MS), userterminal (UT), mobile subscriber station (MSS), subscriber station (SS),advanced mobile station (AMS), or wireless terminal (WT).

Referring to FIG. 31 , a hand-held device 100 may include an antennaunit 108, a communication unit 110, a control unit 120, a memory unit130, a power supply unit 140 a, an interface unit 140 b, and an I/O unit140 c. The antenna unit 108 may be configured as a part of thecommunication unit 110. Blocks 110 to 130/140 a to 140 c correspond tothe blocks 110 to 130/140 of FIG. 30 , respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from other wireless devices or BSs. Thecontrol unit 120 may perform various operations by controllingconstituent elements of the hand-held device 100. The control unit 120may include an Application Processor (AP). The memory unit 130 may storedata/parameters/programs/code/commands needed to drive the hand-helddevice 100. The memory unit 130 may store input/output data/information.The power supply unit 140 a may supply power to the hand-held device 100and include a wired/wireless charging circuit, a battery, etc. Theinterface unit 140 b may support connection of the hand-held device 100to other external devices. The interface unit 140 b may include variousports (e.g., an audio I/O port and a video I/O port) for connection withexternal devices. The I/O unit 140 c may input or output videoinformation/signals, audio information/signals, data, and/or informationinput by a user. The I/O unit 140 c may include a camera, a microphone,a user input unit, a display unit 140 d, a speaker, and/or a hapticmodule.

As an example, in the case of data communication, the I/O unit 140 c mayacquire information/signals (e.g., touch, text, voice, images, or video)input by a user and the acquired information/signals may be stored inthe memory unit 130. The communication unit 110 may convert theinformation/signals stored in the memory into radio signals and transmitthe converted radio signals to other wireless devices directly or to aBS. The communication unit 110 may receive radio signals from otherwireless devices or the BS and then restore the received radio signalsinto original information/signals. The restored information/signals maybe stored in the memory unit 130 and may be output as various types(e.g., text, voice, images, video, or haptic) through the I/O unit 140c.

4.2.4. Example of Vehicle or Autonomous Driving Vehicle to which VariousEmbodiments of the Present Disclosure

FIG. 32 illustrates an exemplary vehicle or autonomous driving vehicleto which various embodiments of the present disclosure. The vehicle orautonomous driving vehicle may be implemented as a mobile robot, a car,a train, a manned/unmanned aerial vehicle (AV), a ship, or the like.

Referring to FIG. 32 , a vehicle or autonomous driving vehicle 100 mayinclude an antenna unit 108, a communication unit 110, a control unit120, a driving unit 140 a, a power supply unit 140 b, a sensor unit 140c, and an autonomous driving unit 140 d. The antenna unit 108 may beconfigured as a part of the communication unit 110. The blocks110/130/140 a to 140 d correspond to the blocks 110/130/140 of FIG. 30 ,respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from external devices such as othervehicles, BSs (e.g., gNBs and road side units), and servers. The controlunit 120 may perform various operations by controlling elements of thevehicle or the autonomous driving vehicle 100. The control unit 120 mayinclude an Electronic Control Unit (ECU). The driving unit 140 a maycause the vehicle or the autonomous driving vehicle 100 to drive on aroad. The driving unit 140 a may include an engine, a motor, apowertrain, a wheel, a brake, a steering device, etc. The power supplyunit 140 b may supply power to the vehicle or the autonomous drivingvehicle 100 and include a wired/wireless charging circuit, a battery,etc. The sensor unit 140 c may acquire a vehicle state, ambientenvironment information, user information, etc. The sensor unit 140 cmay include an Inertial Measurement Unit (IMU) sensor, a collisionsensor, a wheel sensor, a speed sensor, a slope sensor, a weight sensor,a heading sensor, a position module, a vehicle forward/backward sensor,a battery sensor, a fuel sensor, a tire sensor, a steering sensor, atemperature sensor, a humidity sensor, an ultrasonic sensor, anillumination sensor, a pedal position sensor, etc. The autonomousdriving unit 140 d may implement technology for maintaining a lane onwhich a vehicle is driving, technology for automatically adjustingspeed, such as adaptive cruise control, technology for autonomouslydriving along a determined path, technology for driving by automaticallysetting a path if a destination is set, and the like.

For example, the communication unit 110 may receive map data, trafficinformation data, etc. from an external server. The autonomous drivingunit 140 d may generate an autonomous driving path and a driving planfrom the obtained data. The control unit 120 may control the drivingunit 140 a such that the vehicle or the autonomous driving vehicle 100may move along the autonomous driving path according to the driving plan(e.g., speed/direction control). In the middle of autonomous driving,the communication unit 110 may aperiodically/periodically acquire recenttraffic information data from the external server and acquiresurrounding traffic information data from neighboring vehicles. In themiddle of autonomous driving, the sensor unit 140 c may obtain a vehiclestate and/or surrounding environment information. The autonomous drivingunit 140 d may update the autonomous driving path and the driving planbased on the newly obtained data/information. The communication unit 110may transfer information about a vehicle position, the autonomousdriving path, and/or the driving plan to the external server. Theexternal server may predict traffic information data using AItechnology, etc., based on the information collected from vehicles orautonomous driving vehicles and provide the predicted trafficinformation data to the vehicles or the autonomous driving vehicles.

In summary, various embodiments of the present disclosure may beimplemented through a certain device and/or UE.

For example, the certain device may be any of a BS, a network node, atransmitting UE, a receiving UE, a wireless device, a wirelesscommunication device, a vehicle, a vehicle equipped with an autonomousdriving function, an unmanned aerial vehicle (UAV), an artificialintelligence (AI) module, a robot, an augmented reality (AR) device, avirtual reality (VR) device, and other devices.

For example, a UE may be any of a personal digital assistant (PDA), acellular phone, a personal communication service (PCS) phone, a globalsystem for mobile (GSM) phone, a wideband CDMA (WCDMA) phone, a mobilebroadband system (MBS) phone, a smartphone, and a multi-mode multi-band(MM-MB) terminal.

A smartphone refers to a terminal taking the advantages of both a mobilecommunication terminal and a PDA, which is achieved by integrating adata communication function being the function of a PDA, such asscheduling, fax transmission and reception, and Internet connection in amobile communication terminal. Further, an MM-MB terminal refers to aterminal which has a built-in multi-modem chip and thus is operable inall of a portable Internet system and other mobile communication system(e.g., CDMA 2000, WCDMA, and so on).

Alternatively, the UE may be any of a laptop PC, a hand-held PC, atablet PC, an ultrabook, a slate PC, a digital broadcasting terminal, aportable multimedia player (PMP), a navigator, and a wearable devicesuch as a smartwatch, smart glasses, and a head mounted display (HMD).For example, a UAV may be an unmanned aerial vehicle that flies underthe control of a wireless control signal. For example, an HMD may be adisplay device worn around the head. For example, the HMD may be used toimplement AR or VR.

A wireless communication technology for implementing various embodimentsof the present disclosure may include Narrowband Internet of Things forlow power communication as well as LTE, NR, and 6G. In this case, forexample, the NB-IoT technology may be an example of a Low Power WideArea Network (LPWAN) technology and may be implemented in standards suchas LTE Cat NB1 and/or LTE Cat NB2, and is not limited to theabove-described name. Additionally or alternatively, the wirelesscommunication technology implemented in a wireless device according tovarious embodiments of the present disclosure may perform communicationbased on the LTE-M technology. In this case, for example, the LTE-Mtechnology may be an example of the LPWAN technology and may be calledvarious terms such as enhanced Machine Type Communication (eMTC). Forexample, the LTE-M technology may be implemented as at least one ofvarious standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4)LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine TypeCommunication, and/or 7) LTE M and may not be limited to theaforementioned terms. Additionally or alternatively, the wirelesscommunication technology implemented in the wireless device according tovarious embodiments of the present disclosure may include at least oneof ZigBee, Bluetooth, or Low Power Wide Area Network (LPWAN) inconsideration of low power communication and is not limited to theaforementioned terms. For example, the ZigBee technology may generatepersonal area networks (PAN) related to small/low-power digitalcommunication based on various standards such as IEEE 802.15.4 and maybe called various terms.

Various embodiments of the present disclosure may be implemented invarious means. For example, various embodiments of the presentdisclosure may be implemented in hardware, firmware, software, or acombination thereof.

In a hardware configuration, the methods according to exemplaryembodiments of the present disclosure may be achieved by one or moreApplication Specific Integrated Circuits (ASICs), Digital SignalProcessors (DSPs), Digital Signal Processing Devices (DSPDs),Programmable Logic Devices (PLDs), Field Programmable Gate Arrays(FPGAs), processors, controllers, microcontrollers, microprocessors,etc.

In a firmware or software configuration, the methods according to thevarious embodiments of the present disclosure may be implemented in theform of a module, a procedure, a function, etc. performing theabove-described functions or operations. A software code may be storedin the memory 50 or 150 and executed by the processor 40 or 140. Thememory is located at the interior or exterior of the processor and maytransmit and receive data to and from the processor via various knownmeans.

Those skilled in the art will appreciate that the various embodiments ofthe present disclosure may be carried out in other specific ways thanthose set forth herein without departing from the spirit and essentialcharacteristics of the various embodiments of the present disclosure.The above embodiments are therefore to be construed in all aspects asillustrative and not restrictive. The scope of the disclosure should bedetermined by the appended claims and their legal equivalents, not bythe above description, and all changes coming within the meaning andequivalency range of the appended claims are intended to be embracedtherein. It is obvious to those skilled in the art that claims that arenot explicitly cited in each other in the appended claims may bepresented in combination as an embodiment of the present disclosure orincluded as a new claim by a subsequent amendment after the applicationis filed.

INDUSTRIAL APPLICABILITY

The various embodiments of present disclosure are applicable to variouswireless access systems including a 3GPP system, and/or a 3GPP2 system.Besides these wireless access systems, the various embodiments of thepresent disclosure are applicable to all technical fields in which thewireless access systems find their applications. Moreover, the proposedmethod can also be applied to mmWave communication using an ultra-highfrequency band.

The invention claimed is:
 1. A method performed by a user equipment (UE)in a wireless communication system, the method comprising: transmittinga message A comprising a physical random access channel (PRACH) preambleand a physical uplink shared channel (PUSCH); and receiving a message Bcomprising a random access response (RAR), wherein the PRACH preamblebelongs to a first plurality of PRACH preambles which are mapped to aplurality of valid PUSCH occasions, wherein the PUSCH is transmittedbased on physical uplink shared channel (PUSCH) configuration for themessage A, and wherein based on information related to a demodulationreference signal (DM-RS) code division multiplexing (CDM) group of thePUSCH configuration, at least one DM-RS CDM group for the PUSCH isconfigured among two DM-RS CDM groups.
 2. The method of claim 1, whereina PRACH preamble among a second plurality of PRACH preambles which arenot mapped to any one of the plurality of valid PUSCH occasions isavailable to be transmitted.
 3. The method of claim 1, wherein based onthe PUSCH configuration comprising the information related to the DM-RSCDM group, the information related to the DM-RS CDM group indicateswhich one is used for the at least one DM-RS CDM group for the PUSCHamong the two DM-RS CDM groups, and wherein based on the PUSCHconfiguration not comprising the information related to the DM-RS CDMgroup, the at least one DM-RS CDM group for the PUSCH is configured asthe two DM-RS CDM groups.
 4. The method of claim 1, wherein the PUSCH isunable to be transmitted in any of remaining valid PUSCH occasions amongthe plurality of valid PUSCH occasions except for the at least one validPUSCH occasion, and wherein the remaining valid PUSCH occasions areunmapped to any of the plurality of PRACH preambles.
 5. An apparatusconfigured to operate in a wireless communication system, the apparatuscomprising: a memory; and at least one processor coupled with thememory, wherein the at least one processor is configured to: transmit amessage A comprising a physical random access channel (PRACH) preambleand a physical uplink shared channel (PUSCH); and receive a message Bcomprising a random access response (RAR), wherein the PRACH preamblebelongs to a first plurality of PRACH preambles which are mapped to aplurality of valid PUSCH occasions, wherein the PUSCH is transmittedbased on physical uplink shared channel (PUSCH) configuration for themessage A, and wherein based on information related to a demodulationreference signal (DM-RS) code division multiplexing (CDM) group of thePUSCH configuration, at least one DM-RS CDM group for the PUSCH isconfigured among two DM-RS CDM groups.
 6. The apparatus of claim 5,wherein a PRACH preamble among a second plurality of PRACH preambleswhich are not mapped to any one of the plurality of valid PUSCHoccasions is available to be transmitted.
 7. The apparatus of claim 5,wherein based on the PUSCH configuration comprising the informationrelated to the DM-RS CDM group, the information related to the DM-RS CDMgroup indicates which one is used for the at least one DM-RS CDM groupfor the PUSCH among the two DM-RS CDM groups, and wherein based on thePUSCH configuration not comprising the information related to the DM-RSCDM group, the at least one DM-RS CDM group for the PUSCH is configuredas the two DM-RS CDM groups.
 8. The apparatus of claim 5, wherein thePUSCH is unable to be transmitted in any of remaining valid PUSCHoccasions among the plurality of valid PUSCH occasions except for the atleast one valid PUSCH occasion, and wherein the remaining valid PUSCHoccasions are unmapped to any of the plurality of PRACH preambles.
 9. Amethod performed by a base station (BS) in a wireless communicationsystem, the method comprising: receiving a message A comprising aphysical random access channel (PRACH) preamble and a physical uplinkshared channel (PUSCH); and transmitting a message B comprising a randomaccess response (RAR), wherein the PRACH preamble belongs to a firstplurality of PRACH preambles which are mapped to a plurality of validPUSCH occasions, wherein the PUSCH is received based physical uplinkshared channel (PUSCH) configuration for the message A, and whereinbased on information related to a demodulation reference signal (DM-RS)code division multiplexing (CDM) group of the PUSCH configuration, atleast one DM-RS CDM group for the PUSCH is configured among two DM-RSCDM groups.
 10. The method of claim 9, wherein a PRACH preamble among asecond plurality of PRACH preambles which are not mapped to any one ofthe plurality of valid PUSCH occasions is available to be received. 11.The method of claim 9, wherein based on the PUSCH configurationcomprising the information related to the DM-RS CDM group, theinformation related to the DM-RS CDM group indicates which one is usedfor the at least one DM-RS CDM group for the PUSCH among the two DM-RSCDM groups, and wherein based on the PUSCH configuration not comprisingthe information related to the DM-RS CDM group, the at least one DM-RSCDM group for the PUSCH is configured as the two DM-RS CDM groups. 12.The method of claim 9, wherein the PUSCH is unable to be received in anyof remaining valid PUSCH occasions among the plurality of valid PUSCHoccasions except for the at least one valid PUSCH occasion, and whereinthe remaining valid PUSCH occasions are unmapped to any of the pluralityof PRACH preambles.
 13. An apparatus configured to operate in a wirelesscommunication system, the apparatus comprising: a memory; and at leastone processor coupled with the memory, wherein the at least oneprocessor is configured to: receive a message A comprising a physicalrandom access channel (PRACH) preamble and a physical uplink sharedchannel (PUSCH); and transmit a message B comprising a random accessresponse (RAR), wherein the PRACH preamble belongs to a first pluralityof PRACH preambles which are mapped to a plurality of valid PUSCHoccasions, wherein the PUSCH is received based on physical uplink sharedchannel (PUSCH) configuration for the message A, and wherein based oninformation related to a demodulation reference signal (DM-RS) codedivision multiplexing (CDM) group of the PUSCH configuration, at leastone DM-RS CDM group for the PUSCH is configured among two DM-RS CDMgroups.
 14. The apparatus of claim 13, wherein a PRACH preamble among asecond plurality of PRACH preambles which are not mapped to any one ofthe plurality of valid PUSCH occasions is available to be received. 15.The apparatus of claim 13, wherein based on the PUSCH configurationcomprising the information related to the DM-RS CDM group, theinformation related to the DM-RS CDM group indicates which one is usedfor the at least one DM-RS CDM group for the PUSCH among the two DM-RSCDM groups, and wherein based on the PUSCH configuration not comprisingthe information related to the DM-RS CDM group, the at least one DM-RSCDM group for the PUSCH is configured as the two DM-RS CDM groups. 16.The apparatus of claim 13, wherein the PUSCH is unable to be received inany of remaining valid PUSCH occasions among the plurality of validPUSCH occasions except for the at least one valid PUSCH occasion, andwherein the remaining valid PUSCH occasions are unmapped to any of theplurality of PRACH preambles.